Subversion is a great replacement for CVS and a very productive tool for managing code. I began using it last year to track my changes and apply them across my sites. The New Yorg PHP group has a really informative and extensive presentation on using SVN, from setting it up to practical tips for using it. I found the comparision between the two repository storage options, Berkeley DB and FSFS, very informative as I wasn’t really aware of the differences. Another good SVN resource is Simon Tatham’s experiences with Subversion. Notes on how to convert from BDB to FSFS are here.