just for the record, the developers channel is most certainly not the right place to go (restricted access).
the -build channel is a good place if you need help building the project (which would be pretty much a basic requirement if you want to play with the code).
If you want to contribute to the game, there are other channels, but if you want to just study it, #planeshift-build (or the forums) is pretty much it.
As for the original question, it depends on *what* you want to study. You could start at the netmanager and work your way through the various sections of code just as a package would, but if you mainly care for crafting, you could also fast-forward to that section (or follow crafting specific messages as they go through the code).