Here are some good chord shapes to start with, if you don't know them already.

Major 7th chordsMinor 7th chordsDominant 7th chords



These chords are shown in context in the Major Scale Modes PDFs listed on the scales page.

Major Bar Chords A Form.pdf
Major Bar Chords E Form.pdf
Minor Bar Chords Am Form.pdf
Minor Bar Chords Em Form.pdf
Dominant 7 Bar Chords A7 Form.pdf
Dominant 7 Bar Chords E7 Form.pdf

Triads in a Major Key (3 Note Chords)

I.Major Chord Do Mi So1 3 5 (Root 3rd 5th)
II.Minor ChordRe Fa La1 b3 5 (Root b3rd 5th)
III. Minor ChordMi So Ti1 b3 5 (Root b3rd 5th)
IV.Major ChordFa La Do1 3 5 (Root 3rd 5th)
V.Major ChordSo Ti Re1 3 5 (Root 3rd 5th)
VI. Minor ChordLa Do Mi1 b3 5 (Root b3rd 5th)
VII. Diminished ChordTi Re Fa1 b3 b5 (Root b3rd b5th)

7th Chords in a Major Key (4 Note Chords)

I.maj7 Chord Do Mi So Ti1 3 5 7 (Root 3rd 5th 7th)
II.m7 ChordRe Fa La Do1 b3 5 b7 (Root b3rd 5th b7th)
III. m7 ChordMi So Ti Re1 b3 5 b7 (Root b3rd 5th b7th)
IV.maj7 ChordFa La Do Mi1 3 5 7 (Root 3rd 5th 7th)
V.7 Chord (Dominant 7)So Ti Re Fa1 3 5 b7 (Root 3rd 5th b7th)
VI. m7 ChordLa Do Mi So1 b3 5 b7 (Root b3rd 5th b7th)
VII. m7b5 Chord (Half Diminished)Ti Re Fa La1 b3 b5 b7 (Root b3rd b5th b7th)