You want to know how to create and save a custom Inventor drawing template.
To create a customized drawing template, read following wiki section first.
To save the customized drawing as a template use the Save As > Save Copy as Template menu on the yellow "I" of Inventor.
This method is available in the more recent versions of Inventor and is also explained in this wiki paragraph.
The method has the advantage that it does not require you to navigate to the template folder location.
You can also manually navigate and save your customized drawing in the template folder.
This latter manual method is demonstrated in the next video on how to save and use a custom Inventor drawing template.http://videos.autodesk.com/TS14096057.webm
For Further information see: http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=14096057&linkID=9242018&CMP=OTC-RSSSUP01