The Meaning of Life, the Universe, and Everything.
I don't really want to dig into this to much, but on the forge multipart github here as linked above, it says
you only want to use the API and not modify it:
Download the latest dev version from files.minecraftforge.net/ForgeMultipart/
Download the latest dev version of CCL.
Place both mods in your /libs/ folder and link them as libraries in your IDE.
Implementation of all parts of the API should be clean and easy in Java. The minecraft multipart mod is implemented in java as a test case.
So I'd recommend that you download and link that, then dig around for how to add your mod's blocks as a microblock. Doing this will allow you to access all the functionality built into microblocks already.
If you just want to do something like make slabs or walls or something, look at MC or Railcraft slab and wall code.