The Manual : essentially, the bible for the e36.
Here's a PDF version for you cheapskates. The only problem I have with it is that it tends to leave out intermediate steps. For example, “remove rotors”. I had done all the previous steps, and was still unable to take the rotors off. Since there was no description of the process, it took me forever to figure out the problem. Usually however, these problems arise either from over-thinking, or attempting to use brute force when none is needed.