A herpetologoist is someone who conducts research on reptiles and amphibians, therefore as a job, you must be employed by an institute like a university or a zoo (like azr@k said).
If you think you want to study herps there are many opportunities for jobs (you will need a MSc and probably a PhD to get a job though)
I just graduated with a BSc in Zoology with a specialization in Herpetology...I will be attending some sort of grad school next spring
if you are seriously interested in persuing herpetology as a career I may be able to answer some of your questions.
just remember, you have to really enjoy the <b>science</b> part of it
The majority of herpetological research these days focuses on physiology and genetics (there are other topics, but these are the largest fields)...so you have to like things like that first and formost