I completely understand what you feel. I was absolutely terrified of workflows when I first started supporting PDM core functionality. :-)
Since there can be a fair bit of coding involved (especially if you're using workflow expressions to figure out where to route things/how to update objects), a basic Java programming course may be useful here.
The PTC course would be helpful.
I assume that when you said you'd gone through all the PTC documentation you were referring to the Workflow Administration section in the manuals and Online Help, right? I'm not sure exactly what information you're looking for, but there are also a plethora of articles that have been written providing examples for various types of workflow actions/expressions/etc.:
https://support.ptc.com/appserver/cs/search/search.jsp?q=workflow+how+to