A good start

This was one of the first books I used when researching SI both for educational and personal reasons. The first section deals with an SI overview and topics such as what unfamiliar people should know, the characteristics, etc. I found it very helpful, and lent the book out several times both to SI-ing friends and, in some cases, to people who wanted to understand better but were unfamiliar. The back details the S.A.F.E. method, and is interesting but less useful for my specific purposes.