Hello,
I am 16-years old and currently in my last year in high school. I will be commencing college as an undergraduate next fall, 2013. After I complete my bachelor's degree, I am interested in pursuing a law degree, and hence, a career in Nigeria. I am inclined to procure this degree in the U.S.; however, I've done a bit of research and found that Nigerian law firms don't recognize degrees from U.S. universities but they do for those from universities in the U.K., and, of course, Nigeria. That being said, in order to be attractive to these firms, would it be advisable to attend a law school in the U.K. as opposed to the Nigerian Law School, for instance? Will they pick a U.K. law school graduate in preference to the Nigerian Law School graduate? I am really confused. Please help!

Law school in Nigeria is top-notch ooo...

You can do a Bachelor of Law in Nigeria and a Masters in the UK....but either option is not bad.

It is not obligatory you do your LL.B in Nigeria. It could be done in any common Law Country (UK most preferred being where the common Law originated from).
But regardless of any country you go, you still will have to spend 2 years in the Nigerian Law School for the Bar Exam to be eligible to practice as a Barrister and Solicitor in Nigeria.
You should also note that LL.B in Nigeria is 5years unlike the UK where it is done within 3years. Consequently, if your LL.B is done in Nigeria, you will have to spend just a year at the NLS.
Good Luck!