When you create the pages with the wizard the form actions should be setup on the pages for you. The registration and login pages should be posting to themselves. If you login successfully you should be taken to the redirect page specified in the server behavior. You should open up your login page and check the Authenticate User server behavior to ensure that the successful login redirect is set.
If you have any further trouble with this please post back with the pages in questions and the steps you are taking to interact with them.