For starters buy something inexpensive. Something that will not break the bank if it gets lost or stolen; these things do happen in college.
I suggest a factory refurbished laptop. Here are some choices: http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100006740%2050010772%204016&IsNodeId=1&name=Refurbished
We have two Dell D630 laptops running for almost 2 years. Along with this get an external HDD which you will need for backups anyway.