This is an "old school" approach to gods in fantasy gaming and C&C in particular, and a product I have been looking forward to for some time. If you were disappointed with the 3.0 edition of Dieties & Demigods as having far too few deities/pantheons and far too large a set of stat blocks, then this book will appeal to you.
Of Gods & Monsters includes fantasy pantheons for the various races (including goblinoids, gnomes, elves, dwarves, and halflings), the Airdhe pantheon (the default setting of many C&C modules) and a large sampling of real world mythologies, including Japanese, Indian, Roman, Greek, Celtic, Norse, Aztec, American Indian, and Egyptian. Each section provides a representative collection of the deities from each pantheon as well as statistics for their avatars (kind of like it was done in 2nd edition AD&D's Legends * Lore). A plethora of new monsters relevant to each pantheon are included, making this a good addition to C&C's Monsters & Treasures book, as well. A load of new spells are also included, and each deity entry includes suggested benefits clerics of the god might receive.
The plus side of this book is obvious: a convenient grouping of gods from real-world mythology as well as some ready made fictional pantheons, easily inserted in to whatever campaign world you desire. The book is gorgeously illustrated throughout, and has all of Troll Lord's signature artists involved, giving a nice range of variation. As always I enjoyed Bradley's art, but the new arist (who ilustrated the Norse pantheon) did some reall cool stuff here, and I really like his style; it's grown on me quite a bit since Tainted Lands.
The down side of this book isn't really a down side unless you're part of the newer generation of gamers who are accustomed to rigidly balanced mechanics. Many of the new clerical abilities, spells and even some monsters/avatars in this book have interesting stats and approaches. Some struck me as peculiar or potentially unbalanced (not many, just a few). From my perspective as an older gamer this is not an issue; C&C runs like older edition versions of D&D, and those did not arc everything along a specific line of balance. Likewise, C&C is famous for encouraging house rules and customization, so if something seems wonky, excluding or changing it does not cause problems. Personally, I've found nothing with which I had issue here, but then again I'm a more story-focused GM/CK so this book's range of diverse pantheons and ideas will greatly benefit my play style. If you are obsessed with balance, however, you might find some things odd or annoying.
Also, the book could have used a second edit. There were some typos that stood out in certain spots. That said, it's still orders of magnitude better than the 1st printing C&C Player's Handbook in terms of look and editing.
In the end, I would reccommend this book to all C&C players and also to OSRIC/Labyrinth Lord/older edition D&D gamers, as this book would prove equaly useful to such games, I feel. I actually plan to use it in reference to my Pathfinder games, as well.
Value for the Dollar: 5/5