Babysitter

My husband will be switching his schedule to 4 10's including Saturday and my grandma is doing one of our care days. I'm not positive which days we will need help but I can almost guarantee it will include Friday and one other day. I am a teacher and work m-f until 4 p.m. I am very interested in a nanny share, however I have been lucky enough to have family members watch our children for the past 4 years and I have no idea what to expect when it comes to hiring a nanny/nanny share!