I'm working with a teacher at the middle school to help save her from her pile of photocopying and grading. One of the easiest things you can do to save yourself time is simply share a folder in your Google Drive with your class. In this screencast, I'll walk you through how to do it with ease.
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: