How do you hire a part-time nanny?
Put ads on all the places that accept ads for a nanny. When you work full-time it is easier because you need a nanny for full-time, it's harder to match up with a part-time nanny. Talk to them, find someone with experience, call their references, and try to hear how they hang out with kids and what the interactions are like. There will be tradeoffs and you might want to have backup child-care, like grandparents. Preschool is a great way to keep your keets out of home.