Typically each .LRN installation writes up a set of end user documenation that is specific for thier site. This allows them to use screenshots with thier skin and adjust for what packages and features that institution is using. It may also reflect the policies of that institution. A number of institutions have shared thier manuals, help pages etc. so you can use them as examples for creating your own.
Pathways To China Instructors Manual - pathwaystochina.org - dotLRN and dotFolio for a high school level program.
Solution Grove Client Documentation - Documentation for various client sites that use dotLRN, dotFOLIO and OpenACS