Check out this awesome chord encyclopedia. It just might be the best anywhere. Once again, Scotty's color coded charts show you much more than just where to put your fingers. They show you how each note FUNCTIONS in the chord. This is huge. You'll grasp the relationship between chord fingerings and scale fingerings much better if you can see how the chords are structured. This is so important if you're interested in IMPROVISING and SONG WRITING. The key to understanding these charts is below.
It's based on the colors of the spectrum. Think back to Physics or Art class. Remember ROY G. BIV? That name spells the colors of the rainbow in order ... 1 RED ... 2 ORANGE ... 3 YELLOW ... 4 GREEN ... 5 BLUE ... 6 INDIGO ... 7 VIOLET ... so the red dot is always the root note of the scale.