This page lists about a dozen links to key places on the web regarding Tcl/Tk. It's quick and dirty... sort of RAD, just like Tcl/Tk :o)There's a weekly post on usenet's comp.lang.tcl with a subject line of Tcl-URL!, (with some old archives at  [runs from early 2000s through 2006] ), that summarizes news and points to a few central Tcl/Tk sites:
The "Welcome to comp.lang.tcl" message by Andreas Kupries http://www.purl.org/NET/akupries/c.l.t.welcome.html The contents of the page above is mailed to everyone posting to the Tcl USENET newsgroup news:comp.lang.tcl for the first time. This is intended to be a general site for Tcl news, pointers to tutorials, etc, but is awaiting additional community support. http://www.tcl.tk/ An introduction to programming in Tcl http://www.tcl.tk/man/tcl8.5/tutorial/tcltutorial.html A Chinese Tcl/Tk website http://www.tclchina.com/ <<-- This is a link farm?. An organized Tcl resource center can be found at http://purl.org/tcl/home/software/ They also keep info to convince your boss Tcl is a good thing http://purl.org/tcl/home/scripting/ Cameron Laird tracks many Tcl/Tk references of interest http://www.phaseit.net/claird/comp.lang.tcl/ (BROKEN - ALWAYS SEEMS TO BE!)LV I get there - however, the main thing there these days is a link to his search page...
http://phaseit.net/claird/comp.lang.tcl/tcl.html (This might be the right place?) Cetus Links maintains a Tcl/Tk page with hopelessly outdated links http://www.cetus-links.org/oo_tcl_tk.html (broken but available via the wayback machine [http://web.archive.org/web/20110716194506/www.cetus-links.org/oo_tcl_tk.html] The Tcler's Wiki http://wiki.tcl.tk/ Tutorial on using the Tk toolset http://www.tkdocs.com/ Blog on using Tcl http://www.tclscripting.com/ (broken but available via the wayback machine [http://web.archive.org/web/20090322090228/www.tclscripting.com/]) Wiki book on Programming in Tcl http://en.wikibooks.org/wiki/Programming:Tcl The Brazilian Portuguese Tcl'ers Wiki http://www.ricardo-jorge.eti.br/wiki The French Tcl'ers Wiki http://wfr.tcl.tk/ German forum for discussing Tcl http://www.self-tcl.de/forum/
ActiveState, home of ActiveTcl, Jeff Hobbs, and Andreas Kupries: http://www.activestate.com/