If you are trying to decide what to major in as an undergraduate, I’d suggest philosophy. I know, it sound weird, but philosophy revolves around the use of language, and the creation of logical thought processes. The writing that is involved is rather stylized–good exposure to the wacky world of legal writing (for Gods’ sake, don’t major in English or take a lot of creative writing classes–legal writing is becoming more intelligible, but it is still rigid enough to drive a really good writer mad). Any subject that requires you to examine why whatever it is is, and to be able to defend the reason you come up with, is good training for the law.
A second way to look at your major is to consider what areas of law you might have an interest in. I went to law school with a lot of biologist who were interested in environmental law, and several business majors who were heading into coprorate or tax law.
Try to get a good, well-rounded education–general requirement courses are your friends. You would be surprised at how many different things become the subject of a lawyers time. I’m a labor lawyer, some of the people I represent work in technical or scientific professions. If I had a better grounding in science, it wouldn’t be so difficult for them to explain their work to me–and me understanding what they do is often key to what I do for them. Do take classes that are challenging–look at how many papers you’ll be required to write, and how much reading–the more reading the better, because law school is 90% reading. And be involved in your classes–get use to asking questions, participate in any discussions. You will be required to answer questions in law school, so any practice you can get as far as thinking on your feet is helpful. Take debate, in any form, if it’s offered (or just have lots of fights with your friends and loved ones). Oh, political science is another common major, and these classes often include debate opportunities.
Practical experience in a law firm won’t help you in law school–but it may help you know that going to law school is right for you, and it will be a plus when you start looking for a job as a lawyer. The same goes for going to trials–it can be fun, but it won’t help you when professor X asks you to explain the parole evidence rule.
As with undergraduate admissions, law schools do look at your extra-curriculum activities, but they don’t carry all that much weight (I don’t think). Some schools will look at achieving a geographic mix, so a guy from New York who wants to go to school in Oregon may get a second look. Other schools like “life experience”, so the whole “I took 2 years off and now I’m more mature” angle might also get your application a second look. There are several books on getting admitted to law school, above and beyond getting good LSAT results; they’d be more up to date than my advice (mind you, it didn’t keep me from giving you advice).
Oh, and this is really important don’t forget to have fun in college, and continue to have fun in law school. If you get into the habit of enjoying life while you’re still in college, it’s a lot easier to hang on to as you pursue your career.
Good luck, romanticide!!