Steve Holmes has a great tutorial over at Layers Magazine on using the Vanishing Point features in Adobe Photoshop and After Effects. The tutorial is totally free and Steve does a great job.
“Without a doubt, the best new feature in After Effects CS3 is the Vanishing Point Exchange with Adobe Photoshop CS3 Extended. Creating very believable 3D movements from quite simple 2D digital photographs has to be seen to be believed, and the best thing is it’s a pretty easy process. However, there are a few caveats to keep an eye out for, so let’s take a trip into the world of two-dee three-dee!”
Check the whole thing out here.