Study your notes (computer and paper) each night to make sure you understand this system! :) It's not hard to understand, there is just a lot of information. Be sure to know your enzymes and chemicals that break down the different types of foods: saliva (amylase), pepsin, protease, HCl, and bile are the main ones.
Helpful videos:
http://www.youtube.com/watch?v=Z7xKYNz9AS0
http://www.youtube.com/watch?feature=endscreen&v=IxNpXO8gGFM&NR=1
http://kidshealth.org/kid/htbw/digestive_system.html
The Digestion Song!
Game/Quiz
http://www.sheppardsoftware.com/health/anatomy/digestion/digestion_game_quiz.htm
Above picture is from this Website link