This book describes a single wood elven village, with a population of just over 400. But it's actually rather more than that, supplementing Green Ronin's "Advanced Race Codex" (or the earlier "Bow & Blade") with a detailed description and evocation of wood elf society.
Considering that it is only a village, the 95 pages of the book provide as much information as some smaller city supplements. There are only a couple of maps, and one floor-plan, but, given the nature of the village, no more than that is needed - most of the 'buildings' would be trees with two or three hollow chambers inside. Where it shines is the descriptions of the characters, which not only bring the setting to life but provide the basis for numerous plot hooks and potential stories.
The central theme is that the village once suffered a devastating attack from the drow, and that, while the physical scars have all healed, the emotional ones have yet to do so. But, on top of that, the interactions between the various NPCs should provide plenty of inspiration, and a number of plot hooks are explicitly spelled out. There are about 50 NPCs written up here, all with detailed backgrounds and plausible and varying motivations, and I'd say there's enough here to form the basis of at least a short campaign. There's also a handy index at the back to keep track of all the characters, and how they relate to one another.
If there is a problem, it's perhaps that D20 (at least in its D&D form) may not actually be the best system to bring this out - if you're primarily interested in fighting monsters in subterranean labyrinths, a woodland village full of (mostly) CG elves may not be the most useful thing for you. That isn't to say that there aren't plenty of opportunities for wilderness adventuring, or for fighting against the drow or the local orcs, because there are - none of that sort of thing has been left out. But a system with a stronger emphasis on social skills might actually bring out more than the book-as-written. Fortunately, the NPCs are so well described that translating to another system shouldn't be hard, should you wish to do so.
There are, in addition, two new core classes, two new prestige classes, and a number of new skills, feats, spells, and domains, all of which fit in with the elven theme. A lot of this is interesting and original stuff, tying the society together with its theme of spirit guardians and magic gained from ancestor worship.
Overall, this is very well done, and one of the best supplements of its kind that I've seen.