A Bug's Life

One goal of mine is to cook (at least) three things from different cookbooks in the next month, and I've been digging out the books in preparation. I usually cook by chucking things in and seasoning by whim, a little bit of this, a squirt of that, mmm, cumin, always good - but leafing through recipe books is useful to remind me of ingredients or methods I tend not to use, and to pour some whipped cream light on the ruts I wear.

I seem to have three or four main categories of cookbook -
The Appliance Book: it comes with the microwave or Magimix, or you buy it to accompany your slow cooker. Part instructional, with tips for getting the most out of your steamer, how to freeze asparagus (or anchovies, or aspic), and some very strange recipes where it shows you how to do something with your slow cooker that you would normally think is a bonkers thing to try to slow cook unless it was the only cooking appliance you had. They are quite useful, but I don't think I've found a recipe in one that's become a regular or favourite.
The Theme Book: maybe there's a better description for these? Style? Genre? There is some common feature to the recipes. The book of Indian cookery, or vegan, or Gary Rhodes, or River Café. The ones you pull down if you fancy a particular sort of thing, and know the book has several variations. The Novelty Book is a sub-category - the Babylon 5 Cookbook. I could make authentic flarn, if only I had someone to share it with. Chocoholics' cookbooks. N'Orleans cocktail recipes.
The Reference Book: how to make anything, but only one version of it. Yer Delia Smith's Complete Cookery Course, student's first cookbook. That's where I go if I want to check how to make pancakes, or jam, or stock. Useful, but you tend to need to bring your inspiration to the book rather than it providing the spark to generate an interesting dinner.
The Restricted Diet Book: Is this a category of its own? I used to treat them as Theme books but now I'm not just dipping my toe into the food intolerance lifestyle they have taken a more profound position. Sure, I could use the other books and make substitutions, but sometimes you get unanticipated effects when using soy milk instead of cow, or rice flour for wheat, and it is reassuring to go to a recipe you know has been pre-tested for unusual failure modes. They are becoming more like reference books.

So, how do you use yours?

These days when I want to cook something new I usually go to the Internet as well, to gather 2-4 versions and note where the similarities and differences are in ingredients and technique, to get a heads up on what is going to be important about making the item.