TclTutor is a computer aided instruction package for learning the Tcl language. It consists of 43 lessons covering all of the basic Tcl commands and most of the recent (8.0) additions.

http://www.msen.com/~clif/TclTutor.html

[RLH] It was on my personal page so I thought would add the page to the wiki as well. I also believe that Clif Flynt was amicable to having lesson contributions.