I went to a couple of my local libraries and pick up about 5 books and just started reading them. I would do this, because you can read them and gain knowledge, but at the same time not lose a bunch of money. That 100$ (estimate) it would have cost me to BUY the books would be 100$ I could have spent on my tank. About which books, just go to the library and check out everything that looks like it holds a lot of good information. Some are better then others and some are MUST-HAVES for hobbiests, but for just starting I think most of the basic information will be similar.
Sorry, if this wasn't the answer you were looking for.