New Computer Users
Mouse Skills Practice

There's clicking and dragging/dropping practice on this page, and at the bottom of the page there's a link to a download for more mouse practice. Really nice, and entertaining:
MouseProgram.com

or

http://www.pbclibrary.org/mousing/intro.htm

Students can use the mouse to copy capital/small letters, numbers, or anything, in different colors:
http://teachers.teach-nology.com/web_tools/mouse/