Mind Tools
Rudy Rucker
1988 Houghton Mifflin
B
This is an amazing book for teaching the concepts of mathematical logic, 
fractals, number theory, and information theory.  I have never seen these
concepts introduced in such an easy-to-understand fashion.  I recommend it
highly to anyone with an interest in these concepts.  Near the end of the
book, it does go a little overboard with the information theory and becomes
hard to follow.  Happily though, Rucker does a fairly good job of disproving
the existence of god via information theory; for those of you prefer to see
God in the numbers, here you will be shown that the opposite is the case.