I would also recommend three months prior. Question/chat with different people using the different search engines out there, nanny search, this website, care.com, sittercity, or whatever you use, and then try to narrow down to about 6 or 7 people you actually want to meet and interview. Interview once, take good notes and get a feeling for people, and then narrow your list again to about 3-4 for a second interview, and then choose from there. That is kind of how I did it. I also would recommend having them come a few times before starting full time to familiarize themselves with your child(ren).