If you'd like to contribute to the SSI project, you can do so by testing it, writing documentation, fixing bugs, or working on new features.
While using the SSI clustering software, you may run into bugs or features that don't work as well as they should. If so, browse the SSI and CI bug databases to see if someone has seen the same problem. If not, either post a bug yourself or post a message to <ssic-linux-devel@lists.sf.net> to discuss the issue further.
It is important to be as specific as you can in your bug report or posting. Simply saying that the SSI kernel doesn't boot or that it panics is not enough information to diagnose your problem.
There is already some documentation for SSI and CI, but more would certainly be welcome. If you'd like to write instructions for users or internals documentation for developers, post a message to <ssic-linux-devel@lists.sf.net> to express your interest.
Debugging is a great way to get your feet wet as a developer. Browse the SSI and CI bug databases to see what problems need to be fixed. If a bug looks interesting, but is assigned to a developer, contact them to see if they are actually working on it.
After fixing the problem, send your patch to <ssic-linux-devel@lists.sf.net> or <ci-linux-devel@lists.sf.net>. If it looks good, a developer will check it into the repository. After submitting a few patches, you'll probably be invited to become a developer yourself. Then you'll be able to checkin your own work.
After fixing a bug or two, you may be inclined to work on enhancing or adding an SSI feature. You can look over the SSI and CI project lists for ideas, or you can suggest something of your own. Before you start working on a feature, discuss it first on <ssic-linux-devel@lists.sf.net> or <ci-linux-devel@lists.sf.net>.