Well, chords is a whole other ballgame. I'm afraid the Circle of 5ths/4ths won't help you with chords. Most chords are found using trial and error. Once you find something that sounds good, you then analyze it using your theory. Let me take one of the circles and break it down:
Circle 1:
A / G-C-E
D / F#-C-E or D / F#-B-D#
G / F-Bb-D
C / E-Bb-D or C / E-A-C#
F / Eb-Ab-C
Bb / D-Ab-C or Bb / D-G-B
Eb / Db-Gb-Bb
Ab / C-Gb-Bb or Ab / C-F-A
Db / Cb-E-Ab
Gb / Bb-E-Ab or Gb / Bb-Eb-G
B / A-D-F#
E / G#-D-F# or E / G#-C#-E#
(and you right back where you started)
Basically, what u got here is a never-ending 6-2-5-1 progression. Let's look at this by breaking this circle down into even smaller circles by viewing it four chords at a time:
A / G-C-E
D / F#-C-E or D / F#-B-D#
G / F-Bb-D
C / E-Bb-D or C / E-A-C#
This one is in the Key of C:
A / G-C-E is an Am7 chord
D / F#-C-E is a D7 chord
*D / F#-B-D# (not really sure about this chord)
G / F-Bb-D is a Gm7 chord
C / E-Bb-D is a C7 chord
*C / E-A-C# (not really sure about this chord)
F / Eb-Ab-C
Bb / D-Ab-C or Bb / D-G-B
Eb / Db-Gb-Bb
Ab / C-Gb-Bb or Ab / C-F-A
This one is in the Key of Ab:
F / Eb-Ab-C is an Fm7 chord
Bb / D-Ab-C is a Bb7 chord
*Bb / D-G-B (not really sure about this chord)
Eb / Db-Gb-Bb is a Ebm7 chord
Ab / C-Gb-Bb is an Ab7 chord
*Ab / C-F-A (not really sure about this chord)
Db / Cb-E-Ab
Gb / Bb-E-Ab or Gb / Bb-Eb-G
B / A-D-F#
E / G#-D-F# or E / G#-C#-E#
This one is in the Key of E:
*Db / Cb-E-Ab is a Dbm7 chord
*can be renamed to: C# / B-E-G# is a C#m7 chord
*Gb / Bb-E-Ab is a Gb7 chord
*can be renamed to: F# / A#-E-G# is an F#7 chord
*Gb / Bb-Eb-G (not really sure about this chord)
B / A-D-F# is a Bm7 chord
E / G#-D-F# is an E7 chord
*E / G#-C#-E# (not really sure about this chord)
Now, let's put them all together:
Key of CA / G-C-E is an Am7 chord
D / F#-C-E is a D7 chord
*D / F#-B-D# (not really sure about this chord)
G / F-Bb-D is a Gm7 chord
C / E-Bb-D is a C7 chord
*C / E-A-C# (not really sure about this chord)
Key of AbF / Eb-Ab-C is an Fm7 chord
Bb / D-Ab-C is a Bb7 chord
*Bb / D-G-B (not really sure about this chord)
Eb / Db-Gb-Bb is a Ebm7 chord
Ab / C-Gb-Bb is an Ab7 chord
*Ab / C-F-A (not really sure about this chord)
Key of E*Db / Cb-E-Ab is a Dbm7 chord
*can be renamed to: C# / B-E-G# is a C#m7 chord
*Gb / Bb-E-Ab is a Gb7 chord
*can be renamed to: F# / A#-E-G# is an F#7 chord
*Gb / Bb-Eb-G (not really sure about this chord)
B / A-D-F# is a Bm7 chord
E / G#-D-F# is an E7 chord
*E / G#-C#-E# (not really sure about this chord)
You see that? Does that help shed some light on it for you? I honestly don't know who originally came up with this cuz somebody showed me how to play it a long time ago. I just analyzed what he gave me. Once you get used to hearing and playing this, u will do it w/out even really thinking about it. If u still having trouble, I'll try to explain it more for you.