I'm taking Stanford's Introduction to Logic through Coursera and the supplementary reading material makes the following suggestion:
The book presumes that the student understands sets and set operations, such as union, intersection, and so forth.
I have a rudimentary understanding of set theory, however, I am wondering if there is a decent on-line primer or book available which I can review?
There are some good resources here and I do have a copy of Naive Set Theory by Paul Halmos.