I started developing membership websites after a seminar given by the great Bill Myers and Tim Kerber. The idea is simple: Create a website that allows you to share your passion/expertise/wisdom with others - and charge for it. 

After that seminar and joining a few sites myself I felt like "I've found my people!" Never have I met such a great bunch of entrepreneurs willing to help at every level. 

After developing a few sites with limited success, I began researching what made certain sites successful. I interviewed some great folks, asked a lot of questions and bugged a lot of people. 

The end result is Membership Site Bible. I have collected the best practices of the pros, some great insights of others, and my own unique views after having developed a half dozen sites.

So, look around, sign up for some free chapters, and if you like what you see, purchase the book and get 5 interviews with industry leaders, a PowerPoint presentation for selling the concept, and a forcasting spreadsheet to help you do some "what if" thinking.