Good point on textbooks. I would add to that a couple other things:
1) There are a lot of development-related things that I simply want cursory knowledge about right now. Blog posts, textbooks, and the like are great there. The way I go about things is to maintain a list of books to buy and buy them on a FIFO basis. Typically there is about a year lag between when a book goes onto the list and when it comes off and is purchased.
I then work through the book read it, etc. Go on to the next. The book then goes up on my reference shelf and I can go back to it when I need to.
The second group of things I need to learn I have strong knowledge in a related area and really need to work with someone to solve a particular problem. Niche areas of accounting (I maintain accounting software) is a good example of this. I bring myself up to a "conversational" level of knowledge, then work with a customer's accountant to make sure everything is implemented right.
But keep in mind I read about 100 textbooks a year and only a small minority are on IT. Most are hobbies (archaeology, linguistics, history, anthropology, and the like are big topics). It is easy to work an approach like this in.