Adding username and password fields for user login

Hi experts,

I would like to have a user login mechanism similar to the SDN home page. If you notice, everytime you open SDN page, on the left hand side, you can find a username and password fields where you can enter and logon. I would like to have that so that user will be able to logon, and based on the roles, different page was brought up.

I need direction on how to do this. Could you guys please help me by pointing me to documentations, web logs, examples, etc which could help me to accomplish those two tasks: 1. Adding username and password fields on the navigation bar, 2. The coding/configuration that need to be done in order to direct users to specific page based on the roles assigned to them.

Thank you very much,

Johannes