The best places to start would be
here ,
here , and finally
here (which is actually probably pretty similar to the first one).
As for tips on how to do hacks, I'd suggest adding major ones first and working your way down to smaller ones. Big ones that require a lot of changes are more likely to install "properly" on relatively unmodified boards; if you have a ton of little bitty changes made, you have to do more manual searching for things, because even a single character difference will break the "Find" command.
---Skorpion
