Originally Posted by
jkutswings
First, there should be a pet trainer somewhere near the hunter trainer. That's where you (the hunter) learn skills to teach to your pets.
Next, go to your general tab of your spellboook. There should be an icon that looks like a slingshot. That opens the pet training interface.
You can also learn specific skills from a given pet, just through using them awhile, then teach them to other pets.
It's a goofy setup, and I'm glad they improved it for WotLK, but that's how you gain new pet skills in TBC.