In the beginning I had a lot of how-to books -- I was living abroad in a foreign country (wait! I still am!) and trying to teach myself everything about film photography with a manual SLR as I had no other resources to draw from, and the internet was slow and expensive and not easily come by (this was Japan c.2001). But as I got better and more confident in my skills I realized the content of my photographs needed work, and as such, I drew much more inspiration from picture books and those books tend to be the type of photo books I buy now. Even so, the ratio of how-to books still outnumbers the picture books, probably somewhere around 2:1.
That being said, in my recent move back to Japan, the majority of books I brought with me were how-to books, mostly alt processes books, Anchell's darkroom cookbook, and all of Rudman's books, because I know they'll be valuable resources for me here. I didn't bring Way Beyond Monochrome because it's such a heavy book and I knew the second edition would be out this year (which I can't wait to get!). I also brought some 'process/philosophy' books (for lack of a better word since they are not how-to or picture books), like Art and Fear, the Tao of Photography, etc. which tends to me interest me more now as well.