One very important egg can be found on Route 17, and the egg contains Larvesta, the pre-evolved form of Volcarona.
Another way to get eggs, is breeding, where you leave 2 Pokemon in the day care, that are compatible to each other, and different genders. They will then make an egg. (NOT SAYING HOW.....)
For a lot more information on breeding, check this page out: http://pokemondb.net/mechanics/breeding
I don't really understand breeding, but Ditto is compatible with almost every Pokemon
Deino's learnset is on this page: http://pokemondb.net/pokedex/deino