How to create a log in page?

Question

Hello All,

As you probably guessed, I am new to ASP.NET. I created a web application but now I want to create a log in page where only certain users can access my application. I don't know where to start. I do not want to use the Web Adminstator Tool because I have the users and their passwords in a SQL database. Can someone please guide me in the right direction or recommend any articles or reference material?

Also I do not want people to bypass the login screen by typing in the url of the application.

By the way I am using C#

Thank you in advanced