We use NannyChex for payroll and tax assistance. We found our nanny on Care.com, and then called her references. We didn't know anyone who had a nanny or was looking for a nanny at the time, so there was no one to ask for referrals. However, if you have a neighborhood email list or Facebook group, you could try there. The nanny agencies in the area charge a 20% of annual salary placement fee, and that was way too much for us.