Definitely take advantage of the school printers to do big printing jobs like lab manuals, 50 page readings, etc. (Although don't be that annoying person that prints these things off during the morning rush and jams the printer up when everyone's late for class...)
Now that I live in a sorority house where we don't have a computer lab, I decided to get my own printer just for the convenience of printing small things like short assignments or mapquest directions, etc and to have color printing available.
However, I didn't have a printer for my first year and a half at Butler, and I got by just fine. BUT... if you are going to use the labs you need to be aware that the school printers get so much traffic that there is a chance that they will be jammed/out of paper/totally crowded when you have to print off an assigment 5 minutes before your 9:35 am class.
So...just plan ahead and you'll be fine. Free printing at college is not typical, so we have to live it up at Butler, right? : )