Go to the Campaign Workspace:
Click the Add button to start a new campaign.
Give it a name, start, and end date.
Leave yourself as manager or, assign another User to that roll.
Note:
Choose the folder in the Document Manager that contains the letters for this campaign.
Click OK when finished.
With the instance created, you can click on the Edit button to return to the set-up screen and edit things there whenever you need to.
EXAMPLE: This is what I put in for the Reply Card campaign I am starting: