Hackety Hack. I am always interested in learning more and more about the computer and how it works and this website is a great introduction for beginners. Hackety Hack is a small download (not web-based) which will allow you to follow along with some basics lessons which build up to more advanced computer algorithms. The interface is very easy to use and you will be programming commands in no time!
Being that computer science courses are becoming obsolete in some school districts (mine included) Hackety Hack would be a great introduction for students who would like to learn more about programming and how the computer works.