Say for example you want to breed a Sneasle (female) and an Empoleon (male). Lets say that Empoleon knows Surf. When they produce an egg, theres a chance that the egg will be born with a move known by the male (ONLY THE MALE, i think). So by the end, you have a sneasle with 3 moves, and it knows surf. (The eggs will always be whatever the female is, and all moves learned wil be from the male)
So if you want to teach a baby AWESOME moves, teach them to the male first, before you drop them off at the baby-sitters, aka a Love Hotel. I got a pichu that new Volt Tackle, Thunder, QuickAttack, and Rain Dance through this