It depends so very much on what you want to do. Do you want to change the UI ? create extra windows that show certain information? Would you like to play different sounds, or silence turkeys (on-the-side: fix for that incoming soon, hopefully! When I get around to merging the latest changes).
I can only suggest you first learn to program in Java on some easier examples, and then tackle a codebase the size of the salem client.
If you want to persist (and don't mind working within the framework of my code), writing small plugins for my client may be a good place to start getting to grips with the client code:
http://forum.salemthegame.com/viewtopic.php?f=11&t=18135.
lachlaan wrote:censored
Someone still has the training wheels on. You know you can disable the censor, right ?