Kinds of Cookbooks I likeI buy several different types of cookbooks:
1. The technique book. I learned a lot about basic cooking techniques from Julia Child, Pierre Franney, and similar others These lessons have served me well in developing my own recipes, in impromptu cooking, and in decoding poorly written recipes. I wish I knew a lot of this stuff when I was editing recipes for newspaper publication. I'm always learning.
2. The why book. I was trained as a scientist and believe in the experimental method as a path to at least some truths. As such I really enjoy cookbooks that teach me the science or at least the "why" behind what I'm doing. That's why I enjoy the books from the folks at Cook's Illustrated magazine (a/k/a America's Test Kitchen), Shirley Corriher's fine "Cookwise", Alton Brown (though I find the graphics in his books distracting), Arthur Grosser's "Cookbook Decoder", and similar volumes.
3. Books with interesting recipes. OK, I know how to do most of the usual stuff. Now come up with some recipes that make me say "Wow! I want to try that". A lot of these are ethnic books, but others are just plain creative ways of dealing with food. I'm even happier when the key ingredient is not something I have to order by express mail. Our copy of "Fifty Ways to Cook Anything" is falling apart from use.
4. Healthy cooking: Yeah, I eat too much and like all the wrong things. Show me creative ways to reduce fat, increase fiber, use more fresh produce. I'm suspicious of a lot of "healthy" cooking, and I find it hard to judge these books just by leafing through them, but I've found some real winners too. During the summer we're constantly reaching for Jim Bishop's vegetarian pasta book, for example.
5. Behind the scenes: I've written restaurant reviews but never actually worked in a professional kitchen. I'm fascinated by what goes on in there (my brother-in-law, a professional chef has kindly taken me behind the scenes a few times). So I like restaurant books, even if they are short on recipes.
Like some other previous posters, I don't like books whose typography or layout make them hard to read or use in the kitchen (I agree on the complaints about first edition of Moosewood, for example). In my journalism days, I did layout and design and definitely believe form follows function, especially in cookbooks.