I knew very little about set theory when I started, and now I think I know a lot more! This is a very user-friendly mathbook for several reasons:
1. Language! This book actually writes out and explains reasoning and definitions.
2. Resources - this book includes a complete Glossary of all the words, theorems, and concepts, Symbols List, Index, Bibliography, Historical Overview, and Answers to all the Exercises in the back.
3. Examples - every concept has lots of examples to illustrate it, including the use of plenty of diagrams.
4. Transitions and Prior Learning - each section builds directly on a previous section. I never felt like I was looking at something totally new. From beginning to end I was working off of prior knowledge and just taking it a step further, and then another step, and then another . . .
5. Organization - this book is very well organized - every Chapter is divided into sections, and every section is divided into numbered paragraphs. This makes it very easy to read, because every paragraph introduces something new - the focus and direction of the text are clear.
I really liked this book - it's small, easy-to-read, and includes lots of supports for new learners.