Look at public universities in the area (such as University of Minnesota, Winona State University and Metropolitan State University). Public universities inside Minnesota will have a lower cost of tuition than private schools. This is because public schools have in-state funding while private institutions receive all of money from tuition and fundraising campaigns.
Find out what it costs to live in the city around the college. Although the school, more than likely, will offer dorm rooms, it may be cheaper to rent an apartment -- especially if you can split the price with a few friends. Housing around the Minneapolis-St. Paul area is more expensive due to being in a larger city, but smaller cities will have more affordable options.
Talk to each school's enrollment official and find out how much and how often the school raises tuition and fees. Some schools lock you into a specific tuition when you enroll, while others increase the tuition every year you are enrolled, so you end up paying more per credit hour in subsequent years than you did when enrolling.
Think about living at home for a little while in addition to school work. Although this isn't always the "cool" option, it is going to save you a great deal of money, and if you can work during this time it is an excellent option for stock piling some cash before you decide to move out.