Anonymous wrote:4-6 weeks before you need someone, at the most. Most nannies do not know much further in advance if they will be available. Plan for someone to start a week before you return to work so that you can have at least a few days together for orientation/to see if you mesh well (or if you need to make a last minute switch).
I agree with this. I didn't start looking until after I'd had my kids (twins). I started when they were a couple of weeks old, knowing that I'd need/want someone in about 6-8 weeks. I had plenty of options in that time frame (but this was definitely for a nanny, daycare takes longer!)
Good luck!