Here's a pretty compact graphical presentation of the basic chords. This site also has a lot of other good information. http://www.apassion4jazz.net/jazz_chords.html
Bob Frazier has a good website with the theory of chord spelling summarized nicely. http://catalog.com/sft/bobf/music_theory.html
Ralph Patt has listed over 100 common chord progressions and bridges found in over 400 popular jazz songs. http://www.ralphpatt.com/Tonal.html
Ricky Adams' Music Theory site has a series of good on-demand lessons available. Its a good site. http://www.musictheory.net./
Duane Shin sells lesson videos, but also has some very good illustrated chord information available free from this index page on his web site. http://psrtutorial.com/Resources/R_ChordSecrets/r_chordsecrets.html
England's Dr. Bryan Blood's explanations are also clear and helpful. http://www.dolmetsch.com/theoryintro.htm
Here's another "chord analyzer" similar to the PW link posted earlier, but with a little different format. http://guitar.to/piano/index.html
Finally for something a little bit different, try http://members.aol.com/chordmaps/chartmaps.htm
which attempts to "map out" possible chord progressions in a kind of "chutes and ladders" style. It misses some progressions, I think, but it has a different perspective that may be of help to you, at least a little later on.
All these people are saying basically the same thing, but it often helps in understanding something to come at it from several different angles.