Here's an amazing reference book of basic guitar chords -
Guitar Guru - The Chord Book by Karl Aranjo.
It covers important chord concepts, theory and applications. Includes information on basic open string, barre, and jazz chords with lots of clear drawings and charts.
Basic Chords Book for Children
For a child, check-out
Children's Guitar Chord Book, by William Bay.
The diagrams are large and very easy to read. Each chord is accompanied by an illustration of where to place your fingers. And, the book provides easy strum patterns.