Through a lot of sticking my head in the sand, reinventing the wheel and general stubbornness, I\'ve managed to go all this time (years) avoiding learning the built-in ASP.N
This is a 18 part series articles from Scott Mitchell.
It's a very deep explanation of all the features that regards Authentication, Authorization and Membership providers in asp.net. I did never found a better source on this from the same author.
MSDN is the best for ripping the lid off: http://msdn.microsoft.com/en-us/library/ff647070.aspx