Two things come to mind
The C30 is a "venerable" vessel. Been around a lot. Just about everything's ben written about them. Really. 30-35 years...
So, what's on the website should contain just about anything you'd need or want to know.
If that doesn't satisfy you, then consider that the SYSTEMS on C30s and our C34s and C36s are pretty much identical.
So have a look at our C34 website Message Board and the wikis with tons of engine and system related material, AND try the
www.C36ia.org webiste, they're great skippers, too.
http://c34.org/bbs/index.php/board,11.0.html
Good luck. Anything more specific, please feel free to ask here. Oftentimes, answers are not necessarily "boat specific".