Re: How do you tell when to introduce addition meal?
I think you just keep following the baby's lead. When he's hungry, he'll ask for food. He'll see you eating and he'll demand a plate. He'll toddle over to the fridge or the cabinet and start pointing. If it's convenient for you to feed him a third meal, go ahead and do so- but don't feel like you absolutely have to sit him down in a high chair with a well-rounded sampling of solids. At 12 months, a third "meal" could simply be a cup of Cheerios or a bowl of blueberries or something small like that.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"