One way:
- Create your letter (document) with Text you want in Form letter.
- Make sure you have created and excel file with necessary records make sure it's saved and closed.
- Next go to Tools Mail Merge see this movie based on Mac I'm sure you can convert to PC command:
http://www.screencast.com/t/KYjxwdQtS - In last item choose to Printer then when printer opens up choose PDF (hold down) go to Adobe Quality PDF.
- Either one Large PDF will be created or individula PDF's will be create besure to choos all records