Two best books are the APA Standard of Perfection, an old used one will do just fine. And a book by Fred Jeffery called Old English Game Bantams as Bred in the United States (pretty sure that's correct title, search Fred Jeffery Old English Game)
If you need help locating stock let me know, I have quite a few OEGB contacts still, especially in the NW.
Edit: they are wonderful for kids, make great showmanship birds for 4-H
Stromberg's has the Fred Jeffery book for $19.50.
http://www.strombergschickens.com/product/old-english-game-bantams/Bantam-Chicken-Books