Well, since you mentioned a bad financial situation, you can't go wrong giving "Turing Evolved" a try. It's a free book and really quite good, one of the more pleasant surprises I've had after purchasing an ebook reader was the discovery of a large number of free, or really cheap, books that are excellent reads. Keep an eye on this forum in the freebies and recommended reading sections and you'll be astonished at what you come across.
http://www.amazon.com/Turing-Evolved.../dp/B004XR4Y5S