Mail Merge for Opportunity.

Hello Everyone:

Questions for Mail Merge for an Opportunity.

1. Where can I get the template or do I create one

2. Where do if find the Button for the Mail Merge in the Opportunity

3. how do I get the products in the mail merge, I see that there are no Data Fields that you can select for the File Attachment.

If I got to the mail merge templates I see many templates that I can use. Would like to active these.

Any help would be great.