http://www.codeshare.co.uk/blog/tutorial-how-to-create-member-login-and-logout-form-in-umbraco-mvc/

1. Create a login document type and assign the login template to it. You don't need to add any properties to the document type

2. Allow the home page to have the login document type as a child node. In latest umbraco (7.4.3) go to the home document type, click on permissions, add child Login, then save.

3. Create a member in the members section if you don't have one already.

4. Create the login page in the content content tree underneath the home node.

5. Build and run the site, go to the login page and you should see something like this. You can now login with the member details for the member you created previously