Realm of Magic - Trailer Breakdown + Official Info

I wonder how familiars will work. They seem permanent this time, which is awesome. All of my families have at least one cat and one dog, so I wonder how marking them as familiars will work? Will it involve a spell or will it be a simple as clicking on them and selecting the option? Will we be able to buy the other types mentioned in the official description or do you have to cast a spell? Can you have more than one?