Reddit mentions of The Guitar Chord Wheel Book: Over 22,000 Chords!

Theory time! How many are `every chord ever'?

There are several groups of chords, based on how many notes they have:

• triads (C E G)
  
• 7ths (C E G B)
  
• 9ths (C E G B D)
  
• 11ths (C E G B D F)
  
• 13ths (C E G B D F A)
  
  (There are no 15ths, because that repeats the root note.)
  
  (As an aside, playing the last three groups on guitar, you'll usually omit the notes in-between the base triad and the highest one, for reasons of not having enough fingers. For example, a common variant of C9 is just C E G D: x 3 2 0 3 0. The chord `feel' is preserved.)
  
  Each group admits several types of chords, depending on the pitch of the non-root notes. This stems from the fact that chords may be thought of as a set of intervals from the root note: a triad is a third interval and another third interval (C to E and E to G). These thirds can be minor or major.
  
  Hence, there are four types of triad chords:
  
  
• Major (C E G)
  
• Minor (C Eb G)
  
• Augmented (C E G#)
  
• Diminished (C Eb Gb)
  
  And there are 8 types of 7th chords, because a 7th chords is three thirds (e.g. C to E, E to G, G to B).
  
  Theoretically, there are 16 types of 9th chords, 32 of 11th chords, and 64 of 13th chords, by the same reasoning. But here my knowledge (read: skimming of Wikipedia) comes to a halt, because there's some weird stuff at those levels. So suppose that there are 8 types at each level.
  
  Then there are inversions. When you move the root note one octave higher, you still have the same chord but with a different feel. (For example, E G C is a second inversion of C major chord: still recognizable as C but slightly different. On a guitar a common one is C/G, which is G C E, or third inversion: 3 3 2 0 1 0.) So a triad has 2 inversions, a 7th has 3, a 9th has 4, and so on.
  
  Then, of course, there are 12 root notes on which all this stuff can be built.
  
  In addition, once we come to guitar, many chords can be placed in different places of the neck. (C may be open C-shape, or A-shape barre on third fret, and so on. CAGED system is helpful here.) Let's say there are 5 positions of each chord.
  
  There you go for an estimate:
  
  positions 7ths 11ths
  root triad 9ths 13ths
  12 5 (4 3 + 8 4 + 8 5 + 8 6 + 8 * 7) = 11280
  
  You'd need a big poster for that, or small size of each drawn chord.
  
  That's where the guitar chord books come from.
  
  As to your second question, more feasible for a poster, you cannot go wrong by reading e.g. Rooksby's book - it has a good compendium of common chords in the first chapters.

this one is pretty good.