How can I add more fields to my list?

You have the option of adding new fields to your already existing lists at any time. Open the list you would like to add the field to, go to the Settings tab and select the Edit fields option.

This takes you to the second page of the create list wizard, the List fields page, where you can see the fields of the list. To add a new field to the list, click on the "Add field (+)" button.