As I wanted to learn the python GUI,
I searched on internet and found these very nice tutorials on how to built GUI using Tkinter library of python. There are few more GUI libraries available on the internet as you may be aware such as wxpython, but I found Tkinter suitable for my needs and easy to work with. I started learning from UsingPython , it also has a good basic python tutorials if you want to have a refresher course.
The other one was the Python Course which also has some really nice examples and a bit more than using python but both are good and you can start from either one.
Following are library references which are handy to know what things you can change using arguments.