Hi!
I would like to recommend some Tk examples:
Go to:
http://www.activestate.com/Products/Download/Download.plex?id=ActiveTcl
and download ActiveTcl for your platform.
After installation go to subdirectory: demosTk and run widget.tcl (on Win32 you should be able to just double click on it).
It shows all kinds of stuff that you can do with standard Tk.
There is also demo for BWidgets under demosBWidgetsdemo.tcl
Manual for all this can be found here:
http://downloads.activestate.com/ActiveTcl/html/8.4.11/ActiveTcl8.4.11.0.162119-html.tar.gz
Main file is: at.pkg_index.html
Enjoy, Fanda