My screencast is coming, but I wanted to take a moment before everyone runs screaming for the hills for our much deserved long weekend. The last weekend of May. Here is my presentation that I used for the topic. There are lots of links and videos, so it should give you a good place to start and things to think about.
I had a teacher ask me if there was a way to hide or remove students who are no longer in your class. The answer is maybe. It depends on if they are officially dropped from your class and appearing as red in your roster and gradebook. If not, then no, you cannot remove them until they have been unenrolled from the class. If the student is showing up as red in your gradebook though, you can hide them so you don't have to worry about them. Here is a screenshot to help you do it: