If you're investigating CAD platforms, you might find it helpful to take a look at the Using IntelliCAD guide which is available at lulu.com in ebook format.
Using IntelliCAD describes how to use IntelliCAD to draw in 2D and 3D, view drawings, dimension entities, work with layers, insert blocks and external references, add custom programs, and everything else you expect from a CAD program.
The guides are available for a small fee.
Of course ITC members receive source files and output for the IntelliCAD user guides and other documentation as part of their ITC membership. If you're an end user looking for IntelliCAD documentation, contact the ITC member where you purchased IntelliCAD.