Just a quick note to mention an issue I encountered recently. Working with the hosted version of the product - sagecrm.com I was trying to merge with a shared template.
I was working with a shared template and logged on as a non-admin user. I found an order, selected send order and waited patiently for my sales order document to appear.
When nothing happened I set about checking that the document plugin was the correct version and that the template was in the library.
Everything checked out fine so it was a little baffling as to why nothing was happening. Upon a colleagues suggestion I checked my internet settings and low and behold the issue related to my trusted sites or lack thereof.
To make sure that your document templates can generate correctly and are not blocked you should add the Sage CRM url to your trusted sites listing within Internet Explorer
In the case of a hosted install these would be the regional site which you work from as well as the main sagecrm.com on demand page - https://login.sagecrm.com/logon.asp?lang=EN