We have no one either. My parents pretty much disowned me when i was a teenager for being gay. My wife's mom just doesn't have it together and her dad is no longer with us. So we just take turns and fill in where needed. We never go anywhere without the youngest ones. Even date night!
I stayed home for a few years while he worked, Now we work opposite shifts. I take them to school and work late, he goes to work early and gets off early to pick them up from childcare.
@autumnrenea1990, do your research on daycares. I would suggest it. I preferred it over random sitters. I have never hired a sitter before though. Its my opinion. What ever you feel comfortable with.