Not strictly a Sonar-specific question, but sort of. If there is a forum that would be more appropriate, please let me know.
 
I've been told I'm doing this "wrong", though my results are satisfactory to me. But I want to learn it right, especially since now in X3 it probably behaves differently. 
 
Let's say I have a vocal track that I want to sound like it's in a cathedral. Because eventually I will have more cathedral tracks, I decide to put the effects into a bus instead of the track's effects bin. I create a bus called CATHEDRAL. I set the vocal track's output to CATHEDRAL. I put some effects into the bus, and everything is going swimmingly. 
 
Later I add a few more tracks add route them to the same bus. I can turn the bus level up and down and it affects the levels of all the tracks routing to it. Perfect!
 
Now... I'm told this is wrong. I'm not sure I understand what is wrong about it. I think it has something to do with lacking control over how much of the signal remains dry and how much goes through the bus. I've always been happy just setting that dry-wet mix in the effects themselves, but again, this is apparently wrong. Which is where I get confused and shut down and keep on doing things this apparently wrong way.
 
But there are sliders for input, output, gain, send, and one quaintly still called "volume". Is there an easy way to explain this confusery?
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Second question, even less to do with Sonar, even more likely to be more appropriate elsewhere, suggestions for a better forum are welcome. I probably need to join a forum specific to audio engineering techniques, as I have a lot of effects I will need to achieve. Recommendations? (One of my album reviews said "Jim knows every rock-pop production trick in the book" which amuses me no end because I don't know ANY tricks in the book.)
 
For this song, I want to mimic a huge arena concert sound, specifically with someone announcing over the PA "And now, ladies and gentlemen, we are proud to present..." Any specific EQ and reverb settings that might work for this effect?
 

jkoseattle...I decide to put the effects into a bus instead of the track's effects bin. I create a bus called CATHEDRAL. I set the vocal track's output to CATHEDRAL. I put some effects into the bus, and everything is going swimmingly...

I've set in bold the part which is "wrong," or at least unorthodox.  Later in your post you're saying you wish you had more control over wet/dry.  The problem is, you have the track signals going straight into that one reverb bus.  The only control you have over the reverb level for all the tracks is that one bus slider.  Here's the standard way of adding reverb to tracks, each with a different amount of reverb.
 
In a word - Sends.  You direct the tracks to your Master bus.  But you right click in the upper part of each channel strip to add a Send, and you choose the reverb bus for the Send's destination.  The default level will be 0DB - pretty much full.  Move the Sends down on all the tracks, then one by one, move their Sends up to a level that sounds good for each track on an individual basis.
 
You haven't changed the volume level of the tracks, you've just changed the wet/dry ratio with the Send knob.
 
That's the standard way to do it because it works great.  Your method is too limiting in what you can do with the reverb.  With Sends you can have some tracks way up in the face of listeners (dry) or lost in outer space (very wet).
 
Randy
 

Does the answer to this question fall within the terms of service for the forum? :-)
 
There are a lot of people in this forum who know a lot of tricks. I don't think many of the good ones will bite when you ask how should I set my verb or eq? Just click the 'make it sound good' button. It's new in X3. :-)
 
Seriously, you have to play around. Try different settings. Try re-ordering your FX. Come up with a mix you like then start over and do it again.
 
One of the tools I used a lot when learning 'Ins and Outs' was the Vintage Channel.
http://www.soundonsound.com/sos/jan07/articles/sonartech_0107.htm
 

You can certainly use a Cathedral bus to send all your tracks that need big reverb to - and they will get a good wash.  However, you won't have control of how much each of those tracks will get reverb - they all get the same.  And if you turn the backing vox up, for example to get more reverb on them, their relative volume to the other tracks goes up, as well as the reverbed backing vox.  As Randy sez above, if you put your reverb on a send (and set the reverb to %100 wet) you have control of the volume of the dry signal going out the channel to the mix and the amount going out to the reverb unit.  Usually, you will want more reverb on a backing vox than on a lead voice and this allows you to do it.  I hope that makes sense, but if you try it (lead and backing vocal) you'll see how useful this technique is.
 
Gain staging was easier to understand in the old analog days when most things had a knob on the soundboard and direct control over all the volume levels.  You could see and trace the sound.  Gain was a knob at the top of the channel (sound flows downhill like water) to set how much signal came into the track.  It flowed down through the sends where you could tap the sound off - like a faucet.  You could send this stream through the send knob (volume control) to - say - a reverb unit, which "return"ed the signal back to the board through the send return (which also had a volume control).  The reverb unit also had an input volume, and often a volume output.  Meanwhile, the untapped channel signal flowed through the eq to the channel fader.  This volume control went to master fader, as well as the send return(s).  It sounds complex, and is, but not that hard to wrap your head around.  You simply had to know to set all the volume in and outs to about 3/4 up for anything you wanted to hear, and you would get a solid but not overdriven signal (at least on pro equipment).  From there, you could finalize appropriate sound levels, usually using the channel faders.  Digital mimics this analog set up, and it gives you control over every aspect of the sound.
 
For arena sound, I'll leave it to others.
@

Sends are undoubtedly the best way to do it. Remember to set the reverb in the bus to 100% wet.
 
When you set up a send to a reverb bus, don't forget to consider the difference between making the send post-fader or pre-fader.
 
If you set the send as post-fader, then the amount of signal sent to the bus will always be proportional to the level of your volume fader. So for instance, if you set the send knob to -3.0dB and decide you like that ratio of wet/dry, moving the volume fader up and down on the track will maintain that ratio. Note that when you set it as post-fader, you can never achieve a 100% wet reverb sound. There will always be some dry signal. 
 
If you set the send as pre-fader, then the send knob will specify an absolute amount of signal to send to the reverb bus independent of the level of the volume fader. Using this method, you are able to turn the volume fader right down and still hear the 100% wet signal - the volume of which is controlled by the send knob.
 
So the difference between the two boils down to this: with post-fader sends, you control the wet/dry ratio with the send knob. With pre-fader sends, you can use either the send knob or the volume fader to control the wet/dry ratio. 

What you are doing is not "wrong". If it sounds good, then you're ok.
But it is not very flexible or adjustable - If you do things that way, eventually you'll find that adjustments in one area will affect the sound of other components and you'll probably get frustrated.
If this hasn't happened to you yet, you've been lucky.
 
There is a "standard" or "accepted" way to set up effect busses, stemming (ahem) from how hardware mixers were configured in the old days. It's been described by others in previous replies above.
 
Actually I'm surprised that no-one has linked to this cakewalk blog post yet:
Know Your Signal Flow in SONAR
 
Actually I prefer this diagram in the online documentation: Signal Flow

I agree with the idea that it is not wrong. I think it depends on what you want to do. If you want the whole signal processed in the buss Cathedral there is nothing wrong with that  way of doing it. If you want  a wet/dry mixing of the signal use a send. 

jkoseattleNow... I'm told this is wrong. I'm not sure I understand what is wrong about it. I think it has something to do with lacking control over how much of the signal remains dry and how much goes through the bus. I've always been happy just setting that dry-wet mix in the effects themselves, but again, this is apparently wrong.

Well this is wrong in the sense you don't seem to understand the limitations of your approach and the benefits of using sends. If you know that you want all the tracks to have the exact same amount of cathedral reverb then you are fine. If you want the flexibility at mix to add relatively more reverb to one track and less to the other you need to use a send.

As for a general audio engineering forum, try Gearslutz.com. Lots of info there.

Well OK! Nothin' but net for this troupe again! I'm all over sends now. I never really understood the difference between Sends and Buses before, and I still don't, but all I need to know to finally finish "We Are the Elders" I got from this thread. THANK YOU!!
 
Special shout out goes to sharke!
 

sharke
Buncha stuff about faders

Thank you, sharke. I finally got a chance to sit down with this today, brought these responses up, and your explanation of faders really really makes sense and helps a lot.
 
HOWEVER....
 
I have five vocal tracks. They all route through this Vocal Send. How do I edit the wet-dry mix for all five at once? I guess I do it at the Send itself, except I thought someone earlier said to leave the Send at 100%. Anyway, that's fine.
 
So if I want to control the master volume of all five tracks as a group, I still should route them to a different output, right? If that's right, ,it clarifies the difference between how Sends and Buses are used, but in Sonar they look exactly the same in that pane at the bottom. That seems confusing. Am I missing something critical here?
 
 
 
 

jkoseattle
Well OK! Nothin' but net for this troupe again! I'm all over sends now. I never really understood the difference between Sends and Buses before, and I still don't...

Look at this screenshot.  I hid all but a few tracks so you can see what's going on.  Explanation below:
 

 
There are three background vocals.  BG - The bottom control determines where their signals are going.  The red arrow shows they're all going to a bus labeled "BG."  Notice the yellow circle at the top left.  The Sends haven't been activated.  But look at the circle on the right.  The Send on the BG bus has been activated (with a right click, I chose the Reverb bus for the destination of the Send) - I can control the volume of all the vocals with that one Bus slider.  I can control the amount of reverb with that one Send knob on the BG bus.
 
Both the Reverb and the BG buses are going to the Master which goes to the interface.
 
Randy