Title: Tcl for Web Nerds
Authors: Lydia Sandon, edited by Hal Abelson, Preface and Introduction by Philip Greenspun
Web site: http://www.arsdigita.com/books/tcl/
Web site: http://6916.lcs.mit.edu/manuals/tcl/
Description: an online book by the authors to provide basic Tcl information for someone using Tcl as a web programming language.
[Backup site: http://www.viaro.net/users/bradinvancouver/index.html ] [also http://philip.greenspun.com/books/]
Apparently this content is migrating to redhat.com - till then, another backup site is http://www.viaro.net/users/bradinvancouver/index.html .
RS: Worth reading in the introduction: the section LISP without a brain (but with syntax on steroids), which talks bad about Tcl, but on the other hand praises its success as compared to Lisp.