The World of Greyhawk is one of the oldest worlds for fantasy roleplaying. It has a depth and interest to it which is totally unseen in this book. There are far better books based on AD&D - try Elfshadow by Elaine Cunningham for one of the best. Actually, come to think of it, almost all of them are better than Rose Estes' Greyhawk books. Of more interest to AD&D/Greyhawk historians is the GORD THE ROGUE series by Gary Gygax - occasionally badly written, but the ideas make up for it!