This book is a bit dated at this point but is a pretty good resource. It profiles about 30 practice areas and contains interviews from practicing attorneys in each area. You can pick up a used copy on Amazon or Ebay for very cheap.
Science, engineering + patent bar -> intellectual property
Psychology, child development, etc. -> Family Law, Mediation
Accounting -> Tax, Business organization
Foreign Language -> international law, immigration
Math + computer science + foreign language -> criminal law
Look at the Official Guide to Legal Specialties and see what you like.
During law school-get a better idea of what type of law I want to practice, what types of law I would be good at, and what there is demand for in the areas that I am most interested in living. I've read the Abrams book of legal specialties a few times (link is to the book on Amazon). From that book, and other research, so far I am most interested in soft IP (trademarks, copyrights, branding, etc), estate planning, veterans advocacy (specifically with regards to disability claims and the VA-I've read around a dozen VA appeals cases pertaining to the issues that I have), and general contract law (ties in with my past where I performed in theatre pits and as a hired gun for pop acts). I'm also fascinated by 1st and 2nd Amendment law (check out the book Gun Fight). I took a class on 1st Amendment/Mass Media law during undergrad after getting my interest sparked at a law school experience day mini-class. I'm not sure how the last two would translate into careers. I know just enough about different types of law and what lawyers do to know that whatever I think I want to do at this point will probably change once I'm in school.
Graduate with minimal additional debt.
I don't have big law dreams. Financially, I'd like to get a job that pays at or above the 25th percentile for attorneys in the area that I'm most interested ($62k per Pay Scale.com). Between that salary and VA disability (I'm anticipating 30-80% service connected, so $750-$2k/month), I could pay off all of my undergrad debt in a timely manner while living comfortably (if I hit 50% disability, I get free medical for life). My dream/unicorn type of jobs would be working for a music equipment company as a lawyer in a soft IP capacity or working for a theatre company/union on contracts and/or labor negotiations. For those two, I feel like my experience with music gear and playing in theatre pits/freelance work could be beneficial. I'd rather be happy than rich, but I want to reach the level of financial stability where I'm not living paycheck to paycheck.
I'm open to government work, if it is a GS job. I'll have just under 8 years of active duty time on the books when I separate. Getting a GS job would allow me to be closer to getting a government pension.
This is starting to get a bit dated, but perhaps you will find it useful.