Taking notes you can use any word processing program. You'll want a wireless card if your school has wireless internet (or will get it in the next year or two) because law students are online all the time (internet poker is big here). Plus, it helps for research or pulling up a brief in class if you need it.
Also, you're a guy so it's probably not a big deal, but I think that portability is an issue, too. My computer is quite small and I'm glad because I carry so many books and things for school now....much more than I carried in undergrad.
Look for something that won't be obsolete in three years, and consider a warranty. It's nice when your memo is due and your computer crashes to be able to call Dell or whoever and say it's their problem. OH---and get a USB key so you can back up your notes and stuff regularly. It's great to print in the labs, very very stable, and you have to back things up because if your hard drive crashes and you lose all your notes, you'll be a sorry fellow.