I am no KDEPIM developer, but I can give you some general guidelines:
- start with
techbase.kde.org and set up a development environment. See if you can get the app running.
- Now there are two things you can do:
* run the apps, and see what you want to improve. Do it.
* look on the SVN server and on
bugs.kde.org, there is often a 'junior jobs' page or location with easy to do jobs.
Finally, send the patch here. You will get some response, ppl will probably ask you to improve it, and finally someone will commit it in KDE. If you sent some more patches and you improve your work, they will ask you to get a SVN account and commit it all yourself. Or get one yourself on
http://techbase.kde.org/Contribute/Get_a_SVN_AccountMore info on
http://pim.kde.org/development/start.php
Have fun!