However if you are a small team, I think the following tools are of use to you regardless of what process you are using (the version control software are useful for any project size). Many of my students seem to use them when they are doing project work.
- Version One Team edition - A free tool that supports managing agile software development.
- Trac - An enhanced wiki and issue tracking system for software development projects.
- GIT - A free & open source, distributed version control system. I think it is a major upgrade compared to SVN, even if the initial learning curve is steep.
If you run Windows I suggest you use TortoiseGIT as GIT client.
- Mercurial - A modern, open source, distributed version control system (sounds very similar to GIT?). I think the learning curve is not as steep as for GIT, and a transition from SVN is probably easier. TortoieseHG is a good client for Windows users and what I use myself.
In this user-friendly, six-part tutorial, Joel Spolsky teaches you the key concepts.