Biologist by degree, chemist by degree and working profession.

There are universities that offer specific programs in herpetology. But if you really want to do it right. Focus a B.S. in biology, pick a solid minor incase you need to bank some money (Since biologist make chicken scratch). Or do like me and pick a double major (Bio / Chem). Once you've got this down, then go back to a different university after taking the GRE and apply for graduate school. Find a university that has a known professor working in herpetology, preferably one who has made contributions to the topic that interest you (Dixon, at Rice University in Houston, is a good one. Whirler at A&M is another). Getting a masters in biology with a thesis in Herpetology will get you much further in life than just a degree in herpetology. If captive keeping is what interest you most. Possibly go for specific schooling with a B.S. in zoology, and then follow with a masters in biology (focused down to herpetology). The AP courses that will help you the most in highschool is to ensure you get all of your general natural sciences out of the way (AP Physics, Chemistry, General Bio - ensure that they will be accepted as freshman level courses where you are going). This will give you the ability to start focusing your electives in your first semester. You'll need maths - Statistics is a requirement at most levels, Pre-cal or Cal 1 as well depending on the course plan. AP Algebra, should pass for college algebra, and you'll get another out of the way that is kind of your basic level classes.

Check with your departments about research assistantship programs. I did 2 years of field research in the Ornithology department, as well as the curator for the herpetology department (managing the dead specimens). I finished out my final year at the university as a general biology technician, and was able to do some fun stuff with DNA work and PCR analysis for Biogeochemical. . .

Last bit of advise - look for study abroad programs in the tropics. They will give you an edge, and show you the true potential for life as a working field biologist. I was able to study birds / reptiles / phytoplankton for a month in Belize, Central America, through my university, and it opened more doors than any class at the university itself.