Chris and Trish Meyer have a new tutorial at Artbeats.com: Projecting a 3D layer onto others in After Effects, which uses the 3D property Light Transmission in AE. Thy had another recent 3D tutorial there too, on ways to fake reflections in After Effects. Artbeats also has video tutorials for AE 3D by Steve Holmes, including Shadowvision: Create a 3D Scene.
Red Giant TV has Creating and Working with Complex 3D Projects, a stalking horse for PlaneSpace, the relaunch of the very handy 3D layer assistants from Digital Anarchy. Happily, PlaneSpace doesn't add red tints to everything.