Good training courses for Tcl are available. See <URL:http://www.cpu.com/tclcom3.htm> for a list provided by the trainers themselves to the Commercial Uses of Tcl FAQ maintainer Gerald Lester <URL:mailto:gwl@cpu.com> of CPU.com.
There are a number of books that cover different aspects of Tcl, in different styles. You can find quite a collection at <URL:http://www.tclfaq.wservice.com/tcl-faq/part1.html>.
The user community has an excellent tradition for its generosity and co-operative achievement.
Most important of all, though, at least by the testimony of several leaders in the Tcl world, is the quality of material available on-line, for self-directed learning. This poster and its associated Birds-Of-a-Feather night-time session explore the resources in place now, and directions for the future.