These are the slides from the course I held in June, 2007 at ORNL. I improved on the 2006 version by adding more information useful to people at ORNL, a section on performance evaluation, and some additional material and updated pictures. The slides are available in ppt or 2-up pdf format.
I'd say the important prerequisites are a rudimentary knowledge of programming, preferably of the C language, and a desire to learn how to program on a supercomputer! There are many resources on the web to which I point in these slides in case you need more information.
All these slides are copyright 2004-2007 by Rebecca Hartman-Baker. Permission is hereby granted to reproduce these slides for educational, non-commercial purposes only. Please remember that I worked hard in writing these slides and I deserve an acknowledgment if you use them as a source.