Your local bookstore has a lot of cookbooks. Your local library does, too. But most cookbooks are junk . . . they're good for a recipe or two, and idea or three, and then they sit idle.

If you're beginning to build a library of cookbooks, put every book you look at through the following tests. They're all rules of thumb, maybe 80% accurate each. But if a book scores positive on all of them, you've struck gold.

• Judge a book by its cover: Start on the outside. Cookbooks should look and be shaped like friendly reference works, not magazines. Recipe collections that are the size of magazines, and thin, are usually produced with a wasteful emphasis on photography and layout. They're fine for rounding out a well-stocked cooking library with some light flip-and-read material, but if you're trying to build a basic, functional kitchen library, discard them with extreme prejudice.
• Substance over style: Illustrations and photos are good, and modern cookbooks tend to be stylish. Keep in mind, though, that good cookbooks tend to have smaller and fewer illustrations than poor ones. Photos of finished recipes (so you know what a souffle is supposed to look like) are good - but look for a book with photos that are meant to inform, not to entice or impress. Full-page mood-lit photos with more attention spent on the flatware and expensive dishes don't do anybody any good. And no matter what, there should always be more text than pictures, even if the pictures are diagrams.
• Ingredient Quality: Flip through a few randomly selected recipes. If the majority of the recipes require pre-packaged or processed ingredients, discard the book. In particular, things like canned soups and pastas, frozen bread-dough, and those ready-bake biscuits in the cardboard tubes are sure signs that it's time to set the book down carefully and back away.
• The Index: Every good cookbook has one. If the book deals with unusual ingredients or foreign foods, there should also be a glossary and/or shopping guide, and list of places to obtain difficult-to-find ingredients or equipment. Cookbooks are reference books; they should act like it.
• Clarity: Read a recipe from beginning to end, a recipe for something that sounds tasty (if you can't find a recipe for something that sounds tasty, don't waste any more time with that book). Picture yourself making the recipe. Mentally walk through the process. Do you have a clear idea of what equipment you will need, and how the finished food will look? If you find the recipe confusing, odds are the rest of the book will be just as unclear. Clear recipes have ingredients listed in the order that they're used, and provide notes on how things should look and smell at key stages.
• Good Writing: If you have the time, give the writing itself a critical eye. The best cookbooks use comparison to describe textures and colors, warn you about common errors, and give variants for each recipe. The very best cookbooks also put each recipe in context; the writer takes a little time to tell you why the recipe is what it is.
• Extra Details: The best cookbooks include nutritional information for each recipe (total fat, carbohydrates, calories and so on). It's also a good sign when preparation time is included, along with notes describing which parts of the recipe can be prepared in advance (if any).

If you're buying your first few cookbooks, start with general-purpose references! You will get a lot more use out of "365 More Kosher Low-Fat Ukrainian Turnip Dips for Diabetic Expecting Mothers at High Altitudes" after you've mastered the basics. Probably the best "first" cookbook (and one of the best "always" cookbooks!) is The James Beard Cookbook. Beard is a consummate food writer, and this book (first written in 1959) is still one of the simplest, most useful, and most fool-proof general cookbooks any cook can own. Many of Beard's other work is equally impressive. For vegetarians, it's hard to go wrong with Mollie Katzen's Moosewood Cookbook. For those looking to de-emphasize red meat and have a bit more in the way of fish and chicken, Almost Vegetarian, by Diana Shaw, is a genuine masterpiece.