Almost 2 years ago I used this online training simulation to help a school district get their minds around a Novell migration project. This URL has since eluded me and I've had several people ask about it. I just stumbled upon it so I want to bookmark it here.
Want to see for yourself? Start by opening "Step 1" and then click the link to start the animation "Introduction to Terminology." That session alone is worth marking as a favorite. The remaining portion of the training walks through the various migration tools provided at no cost, how they work, how they differ from MIIS, and it references a few good third party tools.
Once you're ready to play around, try out the virtual lab on TechNet to rehearse migration objects on your own hosted instance of a virtual machine. I've referenced this before but no harm in posting the link again.
Other good info: http://www.microsoft.com/windowsserver2003/technologies/storage/default.mspx