Hey, I've been out of high school for 4 years and am about to start some classes toward my b.s. in e.e. as well. I've looked into it alot and the biggest thing you need to refresh yourself on is math(algebra, geometry, trig), and also some physics basics, but high school physics is usually not that indepth so you may need to just brush up a little bit on that. But then again every college is different and you may get more help in one than another, so the best thing to do is talk to a counselor at the college you are going to and find out the prerequisites for your first year classes. That should give you a good idea on what to expect.