Purpose: An interactive community project to teach Tcl scripting.
This page is the basis for a group project to discuss your favorite introductory topics for someone learning Tcl. Is there a topic you feel should be discussed but which often isn't? Also, many beginners are interested in Beginning Tk as it lets them create something impressive with very little work. However, these beginners should make sure they understand the following topics before moving to Tk, since the concepts are, for the most part, foundational infrastructure.
The idea here is to either add a topic above, or pick one of these and start writing a bit. Sign the page if you like.
See also Advanced Tcl for topics which usually come up after someone has a grasp on the basics of Tcl and Tk, and Arts and crafts of Tcl-Tk programming for a large table of contents of this Wiki.
LV: One commonly referenced interactive Tcl tutorial is Tcl Tutor, available at http://www.msen.com/~clif/TclTutor.html . I list others on the comp.lang.tcl launch page at http://www.purl.org/NET/Tcl-FAQ/ .
RS: A hint not only for beginners: due to its interactive nature, Tcl itself is a very good teacher. Start up an interactive tclsh (i.e. not specifying a script file). Type commands in, see how it reacts. Make intentional errors (you can hardly break anything). Read the error messages, they're very often very helpful.
LV I would, however, suggest that they could locate and use tkcon, if tclsh's minimalistic interface is difficult to use. Also, if you are using vanilla tclsh, read up on the history command.