How to redirect user after login
Take a look at the Login Destination and the LoginToboggan modules. They should do what you want.
The first module allows you to customize the destination to which a user is redirected after logging in, registering to the site (7.x), using a one-time login link or logging out (7.x). The destination can be an internal page or an external URL. It is possible to specify certain conditions like referring pages, or user roles, and make the destination depend upon them. You may use PHP snippets to provide custom conditions and destinations. It is also possible to keep users on the currently visited page after logging in or out.