It's quite popular for parents who don't sign themselves to teach their babies some signs. This means babies can communicate before they are able to speak. This lesson and the next two have signs that are helpful when communicating with young children, though they are also good signs for anyone to know. When I taught in a kindergarten, these were the most helpful words that allowed us to communicate with very young children.
• Sleep (I show you two signs for this)
• Awake/Wake up
Finish and more are the most useful signs - as these are abstract concepts that children often want to communicate but cannot. At a meal time, always ask if your child has finished, using the sign. If they haven't, sign 'more'. When they do finish, confirm it by signing 'finish' yourself. By doing this every time, your child will quickly learn the meaning of the words.
I should have included the sign for 'toilet'. Luckily you don't need a video for that. It's just the letter T, fingerspelled twice: 'TT'.