You have taken the first mail merge training course, Mail merge I: Use mail merge for mass mailings, so you're already familiar with the wizard that steps you through the mail merge process. But mail merge isn't always as simple as just adding a name or address as a field. Sometimes you need to do something a little more complicated, such as tailoring a letter to specific recipients, or adding sequential numbers to a series of coupons.
You can do these merges by using the Mailings tab on the Ribbon.