firetooth wrote:So far this has been a great learning curve!
I'm glad that you're enjoying it - and that's exactly how I got into doing audio stuff, there was just so much to learn... and there still is
firetooth wrote:When you change a level on the mixer does it change the level for the WHOLE song
Yes it does.
If you look at the left side of each track there is a box that has the name of the track (you can click on that and there's a drop-down menu that
does things 
) There are also two sliders - one of them is a track volume slider and the other is a track "pan" slider. The "pan" control sets the balance of how much of the track will come out of the left speaker and how much will come out of the right speaker. The track volume slider controls the over-all level that the the track plays.
It is these controls (pan and volume) that are duplicated in the Mixer Board.
firetooth wrote:I might like to bring the level a bit more up on the guitar for the guitar solo and then down again when the vocal returns, if this isn't TOO difficult.
No it's not difficult, though I find it easier to bring the levels down than to push them up.
A good tip for when you are mixing is to grab the meter toolbar (with the playback and recording level meters) with your mouse and stretch it to the full width of your monitor. This will make it much easier to check that your levels do not go too high (It's really important to keep the levels below 0 dB).
To make adjustments to the volume in specific parts of the track, use the "Envelope Tool". You can access this through a button, or by pressing the F5 key. (The F1 key brings you back to the normal Selection Tool. It's a bit difficult to describe how to use the Envelope Tool, so the best thing is to have a look at this page:
http://manual.audacityteam.org/index.ph ... elope_Tool and have a go with it.
Use the Envelope Tool to control the levels in specific places.
Use the Mixer Board (or the track sliders) to control the over-all track levels.
Keep an eye on the playback level and always keep the levels below 0 dB.
When you have mixed it to satisfaction, Save your Project (this will save the current state of your project but does not save the Undo history).
Then select the entire project (Ctrl+A)
Then use "Mix and Render" from the Tracks menu. This will mix the entire project into a single track.
You can then use the Amplify effect to bring the peak level up to (almost) 0 dB. The default settings on the Amplify effect will bring the peak level up to exactly 0 dB, but many people (including myself) prefer to drop it down a little to somewhere between 0 dB and -3 dB (I generally go for -1 dB).
You are then ready to Export your finished masterpiece.
If you plan to burn it to CD, Look in the bottom left corner of Audacity where it says "Project Rate" and check that it is set to 44100 (change it to 44100 if necessary), then Export as 16 bit WAV.