I don't know if I would recommend buying any of these for what you are going to do, but if you have a library or bookstore nearby you could page through them-
From my days of studying for the CVT exams, has all species (handling and basics, typical problems):
Clinical Textbook for Vet Techs- McCurnin
Just because I am a nerd and got these for birthdays/Christmas:
Keeping Livestock Healthy- Haynes
UC Davis Book of Horses- Mordecai/Siegal
An oldie but goodie from my childhood (never got to be a pony clubber ironically enough- always wanted a horse though!):
United States Pony Club Manual of Horsemanship- Harris
Good Luck! Remember they won't expect you to be an expert, just that you want to learn all you can from them. Have fun!!