Windows Authentications with Role Membership

how to use windows authentication ? please guide me ... i need Complete Windows Authentication Tutorial with easiest explanation and examples .... i have got a tender project in which the users will access the website using their windows credentials ... after the successful login they will be redirected to the specific page ... here are few lines of description which is taken from the user manual ... please guide me what this means and how to make it ?? Lines are ....

1- System administrator creates a set or roles and assign the access rights given to each role. Then while adding a new user to system the administrator could link the user with related role.

2- A user could be linked to more than one role, where he will inherent the total of access rights gratned to all linked roles.

3- For best practices of the system, only system administrators should be allowed to create users and roles

4- Select the desired page name to grant access to from 'SITE PAGE' list
5- Select the level of access needed from 'PERMISSION' list.

6-Now the new user should be created and linked to desired roles successfully. Whenever the user attemps to login the system he/she will inherent the access rights given to linked roles.