I'm in the process of self-studying from the very popular Halmos book "Naive Set Theory" and I must say I can say only the best about the book. However, although the book has some excercises I would like if someone would suggest another resource that contains excercises about the substance of the before mentioned book. It doesn't really need to be a textbook, anything would work really. Thank you.
Suppes Axiomatic Set Theory sounds like it's at about the same level as Halmos' book. It might be slightly more rigorous but is intended as an introductory book. The notation is a little different from what I've seen in most other books but it is still well-written and has a lot of exercises.