Video CoPilot is a web site that sells media for use in After Effects. A sales tool that is employed by them is tutorials to teach folks AE. They start from beginner to advanced (including expressions).
Andrew Kramer, the proprietor, has created a new site called Basic Training that provides a comprehensive set of tutorials for AE that take you from the ground up.
Check it out HERE.
This is a great set of tutorials that Andrew has created and it's FREE. Andrew is a great teacher and he will keep you entertained while he teaches you AE. That's a great combination.