I've started a new set of documents on Importing Source Assets (http://dev.wallworm.com/document/166/importing_source_assets.html).
Unpacking GCF and VPK Files (http://dev.wallworm.com/document/167/unpacking_gcf_and_vpk_files.html)
Using Props in Your Scene (http://dev.wallworm.com/document/168/using_props_in_your_scene.html)
Hopefully these docs help some of you explore building levels in Max--and have the opportunity to use some of your game's existing assets.
There is now a video on importing your VMF and bringing in the props:
http://www.youtube.com/watch?v=kAFScjAlxJE