Mail merge is normally used to personalize otherwise standard letters by adding details (such names and addresses) read from a data-file.

How to set up the letter and select the data to merge into it: see Mail merge wizard
Setting up Advanced options – printing, orientation etc.: see Mail merge options
Changing the fields, text and letter files: see Editing a Mail merge file
List of suitable Paper types

Links

Composite document wizard

Mail merge wizard

Text mode wizard

Tree mode wizard