Steps to Create a Template

I am looking for a step by step on how to create a template.

Doesnt have to be all inclusive just what steps do I follow to create one.

Other questions

1. If I open a template make some changes and change the name do I get a new template with those changes (something like a Save As)? or did I just change the only copy of the template?

2. If they delete that newly named template (or the old one with a new name) is there a way to retreive it?