This is absolutely something I love organizing and setting up! I can't count the number of software projects I've done in groups back in college. The good news is there are a ton of great free, open source, ready-to-use software packages you and your team can use. The bad news: you might need your own servers to instal some of the tools since free online services tend to force you to make it (code, resources, discussions) public.
- Source control: Git (great with many users), SVN (Ready-to-go, easy, commonly used, works well with WebSVN for online source), CVS (older source control system).
- Online meetings: Skype, Google Docs, Gmail, etc. Google Docs is by far the best since it allows multiple users to work on the same document at once across the web
- Documentation: Sphinx (Generate manuals, forms, etc..), Doxygen (Automated source documentation generation)
- Bug reporting: Mantis (Simple and easy, ready to go), Bugzilla (Heavy-duty software package)
- Project Management: trac (Merges source control, wiki documentation, etc. into one website), dotProduct (Heavy duty solution)
- Utilities: It is critical that you quantify people's work done on a project. You should never ever judge the work done by a person's lines-of-code written, but it still is good to see who is doing what work. There are many many many tools that I simply can't even list, but one that works well with SVN is StatSVN
Three of my favorite open-source (and free) hosts if you don't mind keeping your work open to the public:
- Google Code Project Hosting: By far the easiest. Projects are automatically accepted, easy to write bug reports, browse code, audit code, etc. but the feature set is limited
- SourceForge: A big and powerful host that has quite a variety of options and features, but can be overwhelming to new project managers
- GitHub: The cool new small (and big now) project hosting
Hope this all helps!