Sets, groups and relations book

[dsfranca]

Hi,
I would like to know if you guys know a good book on sets groups and relations, preferably with lots of exercises. I believe that I am on a beginner level, but I already know all basic concepts, so the text is not that important. It would be even better if it is available online hehe!
Thks!

[qspeechc]

Here is a short and lovely book on Sets, Relations and Functions, freely available for download:

http://www.cosc.brocku.ca/~duentsch/papers/methprimer1.html

[dsfranca]

Thks, I will take a look at it!