Are you going into freshman year? I am assuming you are and have no idea about college. I have been heavily researching into laptops as well (It's a lot of money!). I don't know what major you are, but for most
students the most important factor is durability.
Basically anything with plastic wont cut it. The white macbooks were one of the most durable plastic computers and even they fall apart eventually. If you pick it up by one corner and it has any flex then don't buy it. I can't stress this enough, you might baby your computer for the first month, but soon enough you will be jamming it into your pack without a laptop sleve because it's lost in the mess of your room and you are late for class. This is university afterall.
exception to the plastic rule: lenovo thinkpad
I guess the next important thing is screen size
If you mostly will study at home, the best screen size is probably a 13" computer since they are very portable, but still big enough to get work done without an extra monitor. Of course you will want an extra moniter at home for getting serious work done.
If you mostly will study on campus, get at least a 14" screen, probably 15" is better. This is the minimum size to really have two windows open side by side and trust me you will do this a lot.
Now as for performance, for most students you will not it to be top of the line. I mean if you are doing multimedia type stuff you might, but then you will also probably just have a macbook. Get at least an i5 and preferably a modest GPU and that's more than good enough. If you do go and buy a crazy fast gaming laptop make sure the battery life is decent (it usually wont be).
Finally, even if you have been told that a mac won't work I would still really consider buying one and just installing windows. Apple is completely dominant in academics except for in engineering and computer science and some (outdated?) buisiness programs. I am a science student and every single one of my profs has a macbook.
Here is a pic of the conference last week at CERN
It's not the greatest picture, but I noticed while watching it that there were like 3 computers in the entire room that were not macbooks and there is a good chance that those ones are running linux. Take the same picture in any lecture hall and you will see the same thing.
In summary: Get the mosty portable computer you can find that has the correct screen size for you, get decent specs but don't bother overdoing it especially at the expense of battery life, and above all make sure it's bombproof.