I just finished the glade part of my new tutorial. The C portion should be done later today and the Python part will probably be done next week. GTK+ and Glade3 GUI Programming Tutorial - Part 1
Here is a slightly oder version of my tutorial: http://www.micahcarrick.com/03-02-2006/gnome-programming-tutorial.html
Furthermore, you're in a good place. Ask your questions here as they come up and check out the example code section for some little examples.
Picking up a copy of Foundations of GTK+ Development is a good idea if you like learning from a physical book like I do.