The Heart of Mathematics: An Invitation to effective thinking
Edward B. Burger & Michael Starbird


Chapter Three Infinity
3.1 What does infinity mean?
3.2 Comparing the infinite
3.3 Are Some Infinities Larger than Others?
3.4 The Power Set and the Question of an Infinite Galaxy of Infinities
3.5 Exploring the Infinite within Geometrical Objects

Related:
2.6 Irrational Side of Numbers
?? 0.9999... = 1

It's a text book I own from a course I took last year; you can borrow it.
It's all pretty basic... you know Cantor's Power Set Theorum, Proving that some infinities are larger than others, etc.