How to Create login in ASP.Net and how they manage in whole website??

Question

Hello..

i m mayank. i m doing GNIIT. Currently i m trying to develop my own website.

But i dont know how i manage the logins in the whole website.

The login information has to be saved in database. and from there it has to be accessed.????

How the users login is managed.????

How i manage the session state for the login..??

Plz help me, how i solve it. or what its method..