Assuming you have some knowledge of programming (and a decent knowledge of the Windows API), you'll need the files found at http://www.lsdev.org/C++LSModule.zip
to be able to even compile a LS module. You'll also need to figure out how to interact with iTunes which will likely mean finding an SDK or documentation on how the program works. I'm not sure if Apple provides that information anywhere but it will simplify your task a great deal if you can find it. If they fail to provide any sort of SDK/documentation, you can try to get the needed window messages using a program like Spy++ or Winspector Spy.
Once you have that, the real work begins and you get to figure out how to make the module work the way you want it to. Code it, test it and then ask others to test it. If all else fails, hop on the mailing list http://www.wuzzle.org/list/litestep.php
or into irc (irc.freenode.net:6667 #litestep) and ask the people in there for ideas and help.
Edit: There's an old tutorial that was up on joeblade and is now hosted at shell-shocked http://shell-shocked.org/article.php?id=162
about coding LS modules. It's quite outdated but if you fiddle with it a bit it still gives you the basics of what you need. Most the important parts are still up to date and for the parts that aren't, I'm sure someone would be happy to help you get set up if you tell them where you're getting stuck.