I work in a cafe as a barista. If anyone is looking for a job while at uni, the cafe industry is the place you want to be. First of all because there are so many cafe's, so there is more chance of similar jobs been open. And if you leave one place you will get work at another easily. Secondly because the hours are part time and flexible!
Waiter is a pretty standard job, you could also transfer skills into a restaurant for some night time work, however you will get payed more if you are a talented Barista becuase of the specailty skills needed. I get around $25/h compared to a waiter on around $15/h.
You should do a coffee course to start off with, something to get your nose in the door. I would recommend "barista basics" in the dymocks building in the city(sydney).
Following that you should get into more advanced stuff. I recently did a course with scottie calaghan, 2007 world latte art champion. Get a passion for coffee and you'll get some decent money. Pro's can make up to 100 dollars an hour.
Something to get you salivating
http://au.youtube.com/watch?v=ae7i-usI7aA Theres a whole other world of coffee out there!