The first time I cooked Mexican food was when a friend of mine invited me to her house for a Mexican-themed dinner party. I found a few Mexican cookbooks at the library, and this was the best one. It provides a great overview of traditional Mexican cuisine, not just tacos, enchiladas, etc. What I like best are the sauces: deep, earthy sauces based on purees of broiled peppers, tomatoes, and red onions, a fair amount of hot chiles thrown in, some fresh cilantro, etc. Another great thing the author does is break up the longer recipes into stages, making it very easy to do all the prep for a dish in advance, and then assemble it for service.