Sock Architecture by Lara Neel is all the rage at the moment and for a good reason. Sock Architecture is an excellent reference book for sock knitters; it covers anything and everything you wanted to know about construction, fit, measuring, techniques, types of heels and toes. I really liked how she talks about adjusting and perfecting the fit, making it an excellent source for those looking to adapt a sock pattern you might already be working on to your own taste and style.
The patterns are all clearly photographed, with all the crucial angles properly shown on a white background. There are 17 patterns, each one covering either a new heel or a toe technique, or both. The techniques are photographed and arranged into very detailed step-by-step collages. The best part of the book is probably the number of options Neel arms you with for your own sock knitting: options for top-down toes, top-down heels, toe-up toes, toe-up heels, afterthought heels, a number of fancy heel gussets, there's sure to be something for every kind of foot.