Barb and I were working together one morning, looking for a way to copy the same file into all the student folders. There are many ways to do this, but perhaps the best is a combination of keyboard and mouse action.
Essentially, you need to
1) Hold Down the Ctrl Key, and
2) drag the file across the screen, from one folder into another.
Here's a video screencast by Michael Chalk, where he shows one way to do this:
What about you - how would you share files with your students?