One major thing I noticed in undergrad, was that high school had absolutly zero impact on college. I was a good student in high school, not great, mostly B's and A's (in that order), and that transfered to mostly A's and B's in college. However, I know people who had mostly C's in high school that graduated Summa Cum Ladue (which is a 3.7+ in my UG). I also know of people who had a 4.6 in high school that dropped out of college freshman year. I only had one school even ask me what my high school GPA was (for law school at least).
Its not a major cocern at all. I do disagree a bit with Bigs with the fluff courses. Yes, if you have a few that will not be a problem at all, but you load up with them A) you will be totally unprepaired if law school doesn't work out B) most law schools DO look at that (my aunt works at a t4 law school admissions office, she says that is certainly a factor, but to an extent of course) C) if you can not handle work in undergrad, law school will not be a smart investment. Do good work in undergrad and take courses that will help you in your major and with what you want to do in your career. It is never a smart move to half ass an education. You are paying thousands of dollars, make it worth it. It WILL come back to bite you, I have seen it first hand many, many times.
But thats beside the point. Don't give up if you want to do it. Just go to an ABA school and I am sure you will be fine. Go to the school that makes you happies in undergrad, I chose a small school in central Massachusetts over schools like Ohio State and whatnot, becuase I was happier there, and still go into one of my top choice law schools. If you are happy you will do better. Just start looking into law school the summer of junior year between study coures for LSAT, start thinking about where you can see yourself going to law school, and start looking things over a bit, then summer of senior year take the LSAT and start looking at schools pretty hardcore. It is better to go strait through (so I am told by many) than to take time off, strictly in a getting used to doing schoolwork sense. Going strait through will not help you in admissions.
Hope this helps.