You can begin prepping for a career in zoology while still in high school by studying diligently in biology and taking any advanced biology classes available. Other classes that deserve special attention are math, chemistry and physics.
Another way to work toward a zoology career while still in high school is volunteering or working at a facility in the line of zoology work you wish to pursue. If you would like to work with a specific type of animal, choose your volunteering accordingly.
For those wanting to study avian behavior, volunteering at an aviary may be the best choice. For those wishing to study fish, find an aquarium or sea world to apply to. Those wanting an all-around feel can apply or volunteer at the local zoo, Humane Society or adoption center. Volunteering will get you more acquainted with animals and animal behavior.
The study of zoology in higher education will cover animal, cell, evolutionary and population biology, ecology, behavior, science, and development. You can also further narrow your field of choice by studying mammalogy, herpetology, ornithology, entomology or ichthyologists.
If you cannot find a college or university that offers a zoology program in specific, you should obtain a bachelor's degree in either biology or science -- biology being the more prominent choice. A zoology degree can take up to five years of study to complete and even longer of one chooses to narrow the degree of study after the five years.
While no education beyond high school is technically required to become a zoologist, the more education the better chance you have to secure a job in your chosen field. In this manner, working at a zoo as either a lab technician or biology teacher or teachers assistant should suffice for an entry-level job in zoology.