I've just completed my 1st project using SONAR Platinum!  I mixed the tracks down and burned a MP3.  The MP3 sounds great; however, the volume level is lower than a typical track you hear on a CD.  Is there some rule-of-thumb settings to use when creating a MP3?  What is the best format to use to get 'CD Quality'?
 
By the way; I have BBE Sonic Sweet Plug-ins.

Although that is a somewhat complex question, if you just want a simple solution to get the volume up, you can insert a compressor in the Master bus.  I don't know if it is still included with the current version of Sonar, but this limiter called Boost 11—despite its many critics—could get the level up without messing up the sound too much if you played with the settings.
 
Personally, I let a mastering engineer do the final tweaks, but just for listening for myself before it's time to make a real record, I use EZMix.  There is a separate Mastering module you can buy for it and several of the presets are good enough for most purposes.
 
Before you get to the point of export, though, be sure the low end is not eating up your bandwidth.  For example, most people use the Pro Channel High-Pass filter on almost every track (except kick and bass) to cut out everything below a certain frequency (like everything below 100 hz or so on a guitar).  Sometimes there is a lot of noise, rumble, and even inaudible stuff that pushes the meter up but doesn't really contribute to the sound. Even on bass, I usually cut below 50-60 hz.  Also, some people tend to mix the kick and bass too loud and that really eats up your headroom.  (I tend to err in the other direction.)  For example, you can see a bass guitar that sounds fine pushing the meter up to the red, while a painfully loud high guitar note may just register a third of the way up the scale.
 
Also be sure your overall mix BEFORE compression peaks at a healthy level.  (Some say -6, some say -3).  If the overall level is extremely low, it will be hard for a compressor to bring it up all the way without affecting the sound adversely.
 
Good mastering engineers use a variety of tools and techniques and make decisions based on years of experience and listening in a pristine environment.
 
Some online research will be very interesting, although I am afraid no one will have a simple answer.  The closest thing to a simple answer is mix at a good level, watch your low end, and put a compressor on the master bus—but don't go crazy with it.

Import the track off whatever CD you are using for comparison.  Look at that waveform.  Does it look like a solid block, or does it have some dynamics?  Do the same with your final mix.  Do they look the same?  Probably not.  There's your problem.
 
Before you start mashing your mix with Boost11, check your master fader and the faders on your audio card.  How hot is your mix without doing anything to it?  If you are attempting to Master yourself, remember that these loudness maximizers are going to whack off the peaks as they bring the volume of the valleys up.  You can try Boost11, but I'd also suggest finding a copy of Limiter6 (freeware); it has more knobs to turn, and as we all know, more knobs means better sound. 
 
A few years ago there was a lot of hubbub about the Loudness Wars.  The war is over.  Loudness won.
 
As you squash your final mix, A-B your mix with your CD reference track.  You can get them equal loudness easy enough, but it is going to change the timbre of your mix.  A bit less is better than a bit more.

The accuracy of your speakers can tell you there is more there than  there actually is. There are so many things in that subject. That really is what you will be chasing for a while. Be willing to learn and be willing to be wrong and don't give up.

Make sure your master buss fader and main channel bus fader are not lowered. If you had these lower for monitoring it will render the audio at a lower level...these are E and F in the diagram at http://www.cakewalk.com/D...amp;help=Views.29.html

I use the LP 64 Multi band compressor on my master buss. This is better than using Boost 11 because it will show you which frequency range your peaking in. So it will squash the low end without effecting the other frequencies. Set the attack fast. 
If used properly all my mixes come out at a tickle below 0db. 
I then open them in Wave lab , top and tail and check the average RMS level. If it's around 14db it's loud. If it's above 15db I'll apply Stienbergs Loudness Maximiser and add 1-2 db. My files have plenty of dynamics if you go to my   https://soundcloud.com/john-vere      you can see the results. 

Agreed that there are many far better solutions than Boost 11; however, when someone is new, a multi-band compressor can be confusing and some people don't know where to start.
 
While I agree about keeping the Master fader at nominal level, my bus faders may vary.  Example: I usually have a drum bus, guitar bus, bass bus, vocal bus, keyboard bus, etc.  If I find the overall mix is peaking to high, I can lower levels using the buses without messing up all my automation moves.  Similarly, I can bring drums up, bass down, etc., without changing dozens of automation nodes in the tracks.
 
Of course, classic thinking is to avoid extremes at each stage (track, bus. master), but in the digital domain I think this is less of an issue.  I seldom have a bus fader that is very far from 0, but if I did, I'm not sure I would worry about it too much as long as the signal was clean.  (If that bus is feeding an external device, then it does matter more.)

I agree Konradh. This is EXACTLY what buss faders are for.
 
When it comes to my master buss, I have a chain of T-Racks singles which I absolutely love and I can get a clean 9dB level increase without breaking into a sweat. This is backed up by a Bluecat Metering plug which has lots of useful readouts showing all the common ways of measuring volume/loudness/RMS values and adheres to the K standard

Essentially, you want your individual tracks to be lower than your submix busses (if you aren't using any, learn that NEXT!) and they should be lower than your Master Buss (which should be at 0 =full volume). You'll see this kind of discussion when you google proper gain staging.
There is also a Sonnitus multiband compressor in your plugs.
Here are some useful videos on getting your final levels up.(regardless of whether they are using PT or not)
 
https://www.youtube.com/watch?v=WFXYoab-kAg
and
https://www.youtube.com/watch?v=DekX3nq5fNE 
and the New York Compression method (trick?)
 
http://mixingtricks.kajabi.com/fe/73413-mixing-trick-sample-2
 
Michael

Thanks to you all.  This is the information I was looking for.  I have several things to check out.