Qualifications
"Duh," you're thinking. "I'm a human. I was, like, born to raise children."
Not so fast. Turns out that "evolution" doesn't actually count as a qualification in the nanny and au pair world. You're going to need at least a high school diploma.
To be an au pair abroad, be ready to demonstrate that you can speak English. If you're reading this, then we're pretty confident on that score. To be a nanny, a degree in early-childhood development or elementary education wouldn't hurt. And the more certificates you have in things like CPR and infant care, the better (source).
You'll also need experience in childcare, whether that's babysitting, working in a daycare, or raising your own kids. And you need to pass a background check to make sure you're not a psycho. Funnily enough, a lot of parents don't want Norman Bates taking care of their kids.