portraiture... one of the finest books on portraiture is now out of print, alas. i have studied every image in it countless times since 2000... just great portraits with short notes on the process of making the images, composition, positioning the sitter etc.
jane bown, faces
closeup... this one is a photographer scientist's exploration of extraordinary things around her, from microscopic to larger. just amazing and eye-opening work, with short, sometimes lyrical introductions to out-of-this world [yet of this world] images.
felice frankel and george whitesides, on the surface of things: images of the extraordinary in science
light... for a long time i searched for a really good book on photographing lighting that covered everything, from product to portrait. this book happens to be an indispensable reference. a lot of text, a lot of technical detail, but i think well worth the effort if one is interested in best uses of light.
fil hunter, steven biver, paul fuqua, light - science & magic: an introduction to photographic lighting
composition and design ... this one is one of the better books on the topic. covers everything from gestalt perception, dynamic tension, to graphic and photographic design elements to process. i especially like the case studies, various images made and their issues, leading to the one image that has all the right ingredients.
michael freeman, the photographer's eye: composition and design for better digital photos