I created a pretty comprehensive document on using Samanage from the perspective of technical users. I went through and stripped out all/most of the references to our organization and put in some [insert your URL/name here] comments, but feel free to use this if it helps jump start your documentation.
It's not 100% comprehensive. For instance, it doesn't list anything regarding Problems, linking incidents, etc. but it should at least give you a good start and could be customized for your purposes.
Finally, I threw in a few jokes throughout the document. Feel free to laugh or groan as appropriate. It's 24 pages long, so I hope that lightens the reading:
If you have any suggestions/thoughts, I'd love to here them. At some point we'll create a similar document for portal users and would be happy to share that once we have that created.