This will Create a Word document or a PDF document (automatically converted from PDF, see Preparing to work with PDF)

wizard in case of table, query or simple form wizard in case form with subform(s)
This starts the Mail Merge Wizard.
2.1 Give a name to the process indicating what type of document will be created.
2.1.a (in case if form with subform(s)) select the form to iterate over (when processing multiple records)
2.2 Indicate if you want all records in the data source to be selected or only the current one (see also Select records to process / create documents from)
2.3 Check Print if you want the document directly to go to the printer. If you checked Print (or Store or Email) you may not want to have the document opened at the end of the mail merge. In that case remove the check from Show Document. You can also do that later using Process Designer (see (Not) show created document).
By setting a checkbox you indicate if you want to make use of one or more of the major additional processes, with additional tabs in the wizard appearing. These are discussed elsewhere (Saving documents automatically, Creating an Email)
2.4 Press Next button (->)

3.1 (optional keep or rename the template)
If the template already exists you will be asked if you want to use the existing one. If not, you will be asked if you want to overwrite it. If another process uses this template, you will be informed about it.
3.2 (optional specify a document or template you want to base the template on)
You may already have the text of a contract, or there may already be a template that has the address merge fields in place
3.3 Press Next button (->)

4. Press 'Create template and process' button. When the generation process is finished the Template Designer opens. It allows you to make the template as required by drag and dropping mail merge fields, adding text, etcetera.
From now on the saved mail merge process is visible from the Process Selection dialog and can be started from there.