Good laptop for university student?

I'm in grade 12 at the moment, but am feeling the need to get a laptop very soon. I'll be using this laptop for when I go to university in september, so it has to be a decent/good one. I don't want to get a Mac, since I don't have 1000+ dollars to spend on a computer and my family already owns an iMac. I'm starting to think that I would like one with a touch screen, and can flip into a tablet, but I'm still not 100% sure… I know those are becoming more and more popular. My brother uses an iPad for his power points for uni, and a laptop for his work, so I'm thinking maybe to get one object with both those in it. I'm not overly great with knowing what computers are best, so any help is appreciated. I'd also like to keep it around the 500$ range.