How would I import a project from another DAW that is just WAV files, with one being a click track? How would I align the imported tracks to measures and beats, using the existing click track? I did this a long time ago with a previous version, but I have long since forgotten how to do it.

There are 2 ways:
1.) Export each track from the same timberline and they will all align in the new DAW
2.) Export each track as a 'broadcast wave file'. As this embeds info into the file.
 
CJ

Research "broadcast wave format" and see if you can export your audio clips from the source DAW. When you drag them into SONAR, they will be automatically positioned at the correct start time offset.
 
Failing that, it depends on your source DAW but I imagine you would have to ensure that each clip starts at the same time. Can you edit the source project? I guess a lot hinges on that.
 
DO you know what the BPM of the source project is? If not, you will probably have to import the click track into a new SONAR project, and experiment with setting the time. I wonder if you can use Melodyne to drag the click into a MIDI track, then use SONAR's "Fit To Improvisation" feature to extract the tempo ?
Is the click a tone, or just a non-specific frequency blast (i.e. a click)?
 
I'm sure there are better ways but this is what comes to my mind.

Broadcast wav files are #1 option (if available)
 
Otherwise... I (hope) this only requires the "easy route." You should be able to simply create a new project, then "Import Audio" and highlight all of your wav files. Name them first, and at that point, I would select them all and drag them right to give a lead in measure. From there, the Aim Assist (X) and/or using vertical grid lines in front of the clips (in the track view: View->Display->Vertical Grid Lines->In front of clips) will allow you to drag clips left/right on something that is obvious in each track vs the click track. Be sure that "snap to grid" is off while doing this, zoom in appropriately, and when finished bounce them all to clips.
 
The less easy route is if this simple alignment does not work and there is drift within the song requiring audiosnap, but initially I would assume the stems are in time with each other.

Thanks. I know how to import tracks, I know about BWF, etc. These tracks don't have a BWF timestamp, which doesn't matter anyway, because what I want to do is align the tracks to Sonar's beats and measures, using the existing click track, which is on one of the tracks I am importing. the tracks are all the same length, so they are synced with themselves, just not to Sonar's project beats and measures. As I remember, there was a way to tap in a tempo map along with the song on a MIDI track and then have Sonar align the tracks to the newly created tempo map. I guess I could do that, but I want to use the existing audio click track and have everything end up aligning to beats and measures, so I can add more MIDI tracks that align to the existing audio. I am imagining this would have something to do with Audiosnap.

To change the audios tempo, you need to use Audio Snap.If its not at the new click tracks tempo. There are videos for that.
Audio doesn't follow project tempo, only MIDI does. so to align it to the new projects measures and beats, you end to know the tempo of the tracks at which they where recorded at and set the new project to that tempo. Then all you need to so is enable audio snap to measures and import them.

 I did this recently. I'm not in front of my PC right now ( i'm goofing off at my day job) ,so excuse me if my terminology is a bit off  .
  I selected all the clips and dragged them into a blank Sonar project. The song was recorded  with a steady drum loop through the whole track for timing. I didn't know the bpm off the loop.
  I tried using Audio Snap by editing the timing map and selecting timing from the loop.That didn't work.
  I then went to the timeline. I right clicked and selected " set beat to now time" and entered beat 1,measure1, and went to the second measure and did the same.
  Sonar set the project to the proper tempo and everything aligned with the grid perfectly. 
 

Vlar
Thanks. I know how to import tracks, I know about BWF, etc. These tracks don't have a BWF timestamp, which doesn't matter anyway, because what I want to do is align the tracks to Sonar's beats and measures, using the existing click track, which is on one of the tracks I am importing. the tracks are all the same length, so they are synced with themselves, just not to Sonar's project beats and measures. As I remember, there was a way to tap in a tempo map along with the song on a MIDI track and then have Sonar align the tracks to the newly created tempo map. I guess I could do that, but I want to use the existing audio click track and have everything end up aligning to beats and measures, so I can add more MIDI tracks that align to the existing audio. I am imagining this would have something to do with Audiosnap.

 
If the tracks all start at time zero and it's just a question of matching SONAR's project tempo to the fixed tempo of the click track, and that tempo is known, you can just enter that tempo directly in the transport module, and you're done (assuming the click was DAW-generated). If the tempo is fixed, but you don't know what it is, You can just set a single beat using Set Measure/Beat At Now (Shift+M) on a click that's 8 or 16 bars into the project, and that should do the trick. If that ends up being super close so some whole number tempo, you can probably just undo that and enter that rounded tempo in the transport module.
 
If the click has a variable tempo, you can use Audiosnap's Set Project from Clip function or use Set Measure/Beat At Now to align the timeline manually at multiple places as needed. But it would be a lot easier to have the project originator export a MIDI track that you can copy tempo changes from.
 
 

 
There will be no MIDI track, just an audio click track, as I said. I may or may not know the tempo. I need to have Sonar derive the tempo from the click track and align the Sonar project quarter note beats to the pre-recorded audio quarter note click track beats. Maybe Sonar can make a MIDI track from the pre-recorded audio quarter note clicks and then sync the measures to that. I am trying to describe this the best I can.

If it were me, I would start by importing just the click track into the project, play it with the metronome off, count out through measure 8, tab to the transient that should be 9:01, and Shift+M to set that beat. Then enable the playback metronome, and see how the project aligns as a whole. If it's a fixed tempo, you might be done at that point (or after setting the rounded tempo as I mentioned earlier). If it just drifts a little and consistently, undo that Set, and do one closer to the end of the clip.
 
Only if there's a lot of variation, and more than you can handle with Set Measure/Beat At Now, should you have to use Audiosnap's Set Project from Clip. But if you do, it should be fairly straightforward on a click track. It generates tempo changes that aren't right on the grid, which I find messy, but the discrepancies aren't audible.
 
Once you have the project aligned to the click, you can bring in the rest of tracks. You can do that at any time, but It might be easier to wait until you've worked out the timing with the click track.