An absolutely terrific book!

It gives people with no experience in version control a great overview over the possible methods along with a comparison of their benefits.
It helps veteran CVS users understand the differences between CVS and Subversion, and helps them migrate.
It covers questions that you'd find in a FAQ.
It serves as a manual and reference.
It's not too big, and the style of writing is easy to follow.
On top of all that it's fun to read :)

I really enjoyed reading it and got through it very quickly. If I continued to write on in more detail now people would assume that I'm on O'Reilly's payroll so I'll just say:"I'm not!" and "Go and buy it!" ... the latter being true for people who a) contemplate using version control and b) for people who find CVS' shortcomings to outweigh its benefits. :}