mudgel
The help file and ref' guide are under utilised and under appreciated.
I like Scott G's Power books as a teaching tool but there's nothing wrong with the docs included with Sonar.
I agree, particularly concerning the Reference Guide.
I try to read the reference guide cover to cover. I have learnt one thing after years in research, though. It is often worth looking through the contents in a book before the index. Sometimes, when looking for a particular item in an index, you can miss the entry you need because you don't know the exact terminology. A search through the contents can give a much broader view.