TITLE: Book/article/tutorial as an introduction to Cardinality
QUESTION [7 upvotes]: I study CS, but on the first semester I have a lot of mathematics. Of course, there is an introduction to set theory and logic. Recently, we had lectures about cardinality, different kinds of infinity, countable sets etc. I know the basics, but I don't understand many ideas as I would like to understand them.
Well, I am looking for a book/article/tutorial/etc. which is a good explanation of cardinality, countable sets, idea of different kinds of infinity and cardinality of sets of different functions. Now, I only need sources, which cover the basics, but I don't mind if You post something on higher level (but introduction stuff has greater priority).
PS: I was looking for similar questions on this site, I've found for exaple [1] and [2], but it isn't what I'm actually looking for.
I woluld appreciate You help.
[1] Cardinality of set of real continuous functions 
[2] What Does it Really Mean to Have Different Kinds of Infinities?

REPLY [2 votes]: There is Set Theory, by K. Kuratowski and A. Mostowski.
It's dry as dirt and yet for some reason I loved reading that book.
If it's available in your library, I'd take it home and see if it works out.