Petopia has posted a nice guide to feeding your Hunter pet, from the basics all the way up to the math behind each pet feeding tick. If you've ever played a Hunter, you already know that when your pet gets unhappy, you need to feed it, but did you know that the difference between your pet and the food's level affects just how happy the food makes it?
The guide also has some interesting info about "raw fish" and "raw meat," two food categories recently added to the game. At this point, apparently raw fish and meat are interchangeable with their cooked counterparts, but in the future, Blizzard may create pets that only eat raw food, or that are only interested in eating cooked food.
Anyway, if you've played a Hunter all the way to 70, most of this will be very familiar to you (even if you only knew that an unhappy pet wanted food). But as a very general overview of pet feeding tips and resources, it's a good one.