A good way to spice up your D&D gaming sessions. The selected races available as potential PC's are diverse and believeable, from Pixies to Orcs. The book contains good role-playing notes on racial backgrounds/tendencies and how to bring humanoid races into a campaign. It certainly is interesting and well-written. However, the sections on superstitions and monstrous traits seem grossly inappropriate for some character types.
Still, at heart I think the complete book of humanoids was a great idea. I just started running an ogre mage in a Forgotten Realms campaign and he is definitely one of the most interesting characters I have ever played. It's a fun, unique challenge to play a character with such a radically different perspective from the typical human/demihuman. I do think you need a skilled, experienced dungeon master for humanoid characters to work successfully.
Novice DM's should not include this book in their campaign-- handling the racial details isn't easy, and some of the more powerful humanoid races could get out of control without a good DM to keep 'em in line