GOOD tutorial(s) for learning the ASP.Net security/authentication framework

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.Net support for web application authentication, users and roles. Part of the reason is that rolling my own originally seemed like less work than getting my head around all the different layers of optional abstraction provided by the ASP.Net security framework and as such I came up with a nice library that worked fine for me.