Upon installation, and before you start using Planner, you should create groups. With groups created, project managment will be much easier to deal with. To create a group you will need to click on the Resources button and then click on the Edit Groups entry in the Action menu. Once you add the new group, you click on each item in the group (Name, Manager Name, Manager Phone, Manager Email). You can also select a specific group to serve as the default group.
Once groups are created, you will see them as a drop-down when you add a new resource(s).