The Thinktecture v3 Identity Server is a collection of highly customizable modules, so there is enough code to write to configure it the way you want. Thinktecture wiki have a good hello world example that might be enough for you:
Hello World
After that, download the samples, find the one that most closely matches your situation, and based on this. In particular, you will want to configure the database to save registered users. The associated MembershipReboot project is typically used to access data, as well as the MembershipReboot.Ef addon, which will automatically create your database using EntityFramework.
MembershipReboot - , , .