http://shrubbery.student.utwente.nl - This is one of the better 750 sites. It is chock full of repair stories. Johan and Sean are quite funny, their broken English adds a dry wit to their writing.
http://www.bimmerboard.com/forums/e32/ - A good 750 message board (there are also boards for other models). Not a ton of posts, but a few knowledge and helpful folks.
