Well, it seems that most people has suggested books that go towards the high level side (technical or management wise) of programming, but I believe going in the oposite direction (the low level one) can also be very productive, for instance learning assembler lets any programmer understand how things really work.

So I would recommend See MIPS Run and don't get bewildered but the fact that it is about MIPS processors, for learning purposes it is far better than going the x86 way!!!