I'm not affiliated with Cornell but I do know a thing or two about college applications.
For starters, you should go on ahead and start practicing for the SAT, no matter how smart you are. I made a big mistake when I was in high school and didn't practice. The reason that this is a mistake is that most people, especially really smart people, practice very hard for the SAT. If you want to get a competitive score, then you need to practice like everyone else does. It isn't fair and it skews the test scores for everyone that doesn't realize it, but that doesn't make it any less true.
Fortunately, most libraries have a bunch of books on how to practice for the SAT, so you don't necessarily have to buy a copy for yourself.
While you are at the library, you should probably check out the 2007 Princeton Review Guide to US Colleges and the 2007 US News Ranking of US Colleges. These books contain lots of good information about what different schools are like and how selective a school is. Since Cornell is a very selective school and there are a lot of people that want to go there for undergraduate education, you will want to pick out some other schools that you would be interested in attending.
Since you are interested in field that pretty much requires you to attend grad school in order to find work, you don't necessarily need to attend a top-tier university as an undergraduate. In fact, since you live in New York, I would suggest that you apply to some of the very good public schools that are in your state. What matters most when applying for jobs is the last school that you attended, so if you get your doctorate from Cornell, people aren't going to care about where you got your undergraduate degree. Since attending a private school like Cornell is very expensive as an undergraduate unless you get a lot of scholarships, it is more cost effective to attend a respected public school in your home state. Graduate programs care most about your grades, your undergraduate research experiences and your GRE scores. So just be sure that you get good grades, are involved in some sort of research as an undergraduate, and practice very hard for the GRE your senior year of college.
That being said, it is pretty hard to get a job in science with just a bachelor's degree, so go to the best school that you can afford!
