Dave, I would find some good theory sites,or books to start. In the world of rock and roll, I have found only a handful of people who have actually studied music and how it works. I started on this quest because after high school, I continued to study only by reading interviews. One of them intrigued me.
Sting made the statement that within the chord progression, a chord is not defined until the bass player plays his note.
When you look at that, you will be amazed at how many chords we bass players actually create because of note choice.

http://www.astronomy-awards.org/Resources/Music/Music_Theory_Instruction.htm

http://www.dmoz.org/Arts/Music/Theory/


http://www.people.vcu.edu/~bhammel/theory/resources/index.html

Thanks for the reply.
I have a good understanding of the basics of chord structure, such as root third fifth and such. My real interest at this point is in figuring out chord note substitutions and inversions based on the progressions. My problem is that, although I feel I know what sounds good, I would like to understand how it works.
DRoot

One thing that helped me immensely as a young guy, was having a keyboard around. One can then actually visualize the structure. i.e., a C major triad, C,E,G....one then can "hear" that C is the root note, E is the third, G the fifth, etc. The added advantage is that you can actually count the steps involved....more easily for me, than doing it on strings.

Adding extentions, say, a B natural, to make a Cmaj7th, or a flatted B to make a C 7th, is then more easy to understand in the minds eye.

Keyboards are cheap nowadays, walmart, etc. Just my 2 cents. They just help to lay out the aspects so linearly.

Good luck!
Craig

Check this guy out. He has some videos on Youtube. It may help with what you are looking for.

http://www.billharrisonmusic.com/