"Chad Perkins is one of the world’s leading After Effects trainers and experts, through his books and online tutorials on places like Lynda.com. In this wide ranging interview we discuss cool stuff in After Effects that many users miss, how he got started in training and how today’s short attention spans..."
There's more on Chad's work at Adobe TV and referenced here at AEP, along with several news notes on Lee Stranahan. Tip Squirrel hosted Chad's article Scott Kelby, Andrew Kramer, and the Decline of True Art not too long ago.
It should be noted that before free training exploded all over, Brian Maffitt's Total Training was the "cheatsheet" for AE, particularly for in-depth explanations of many filters now built-into AE -- like WaveWorld and Caustics (mentioned by Chad). One fav was the Particle World demo on what each slider did with settings displayed onscreen. Motionworks posted a different example last year; see CC Time Blend FX with Brian Maffitt.