Read the textbook portions listed in the syllabus/schedule
Read any links in the syllabus/schedule
Read your class notes

And very importantly -    PLAY WITH THE SNAKE!!!

goof around in both the SnakePit (the interpreter window) and as a "real" programmer in the pyProgramming window (the editing window)
to have a hands-on learning experience.
You should practice the things that were shown in lectures, trying to make them not work - or finding out that the prof messed up!
Bring questions and interesting discoveries to the labs and maybe you can "stump the lab worker? (or me)
this will count towards your "participation" grade in the labs]