Just make sure you do your homework before every class (so it should be on completed - but even 75% often seems to work), and that you do your presentations / term papers before the term is over (check under term days left in the career panel). Also make sure you always edit your work to get it to a higher quality. Presentations need to be done during the day (click on "give final presentation").
This alone should definitely be enough to pass. Want to be really sure? Study the day before or of the exam by purchasing the university textbook (can be done from any bookshelf) and click on study + whatever course you have an exam for. If you do this until you get the "feeling studious" confident moodlet right before the exam, you will definitely ace it. Hope that helps :)
ETA: one more thing - when they're in class set them to "actively listen" or "take notes" :)
