I know this isn't game specific, and may not be what you're looking for (if it's not, please cheerfully ignore it ).

If you want to really understand matrices, first you need to understand linear algebra (which emcompasses a lot more than matrices, contrary to what many introductory texts might have you believe). This is an absolutely awesome introduction to the subject. I have no idea why it isn't still in print, especially as it was a Dover publication. When I was an undergrad in Rutgers I convinced one of my professors to use it as the textbook for his course when he told me he was looking for one (I probably saved each of his students about $40). As he put it, the textbook they were using was 'bass ackwards', teaching matrix theory first and vector spaces second.

The nice things about the book: it doesn't start with matrices but it does get to them - so you don't confuse vector spaces with matrices. Answers to all the exercises and questions (even the true/false ones) are painstakingly detailed in the book so you understand why the answer is what it is. Yes, it's math, but if you're going to work with these things, you may as well understand what the hell you're doing. I can't imagine more knowledge hurting you

From Amazon it's all 3rd party sellers, so "new" is stupidly expensive. Used-Very Good though is about $12 shipped, which is a bit less than it cost originally, IIRC.