You can download the owners manual here: Mercedes-Benz - Home of C, E, S, CLS, CL, SLK, SL, R, GLK, M, GL, G Class

Mercedes charges for access to the workshop manual. It is via a system known as WIS. If you are looking for general information and DIY for simple tasks, you can find it at this and other forums.

Ball joints in the front suspension are a bit of a weak point on this model. Best get that noise looked at pronto, it could be a safety issue. Not too difficult nor expensive a repair.