I've heard good things about Honey Tree on 6th st (I think that's what it's called. It's honey something) and Little Tree in Madbury. We are looking at both of those and have had friends who really like them. I believe both have wait lists though for infants - most places do.
I have a friend who has used Garrison Learning Center and enjoys the care her children receive. Right outside of Dover is Kids Culture on Route 108 in Somersworth. Stratham is a little further from Dover but not sure where you work and there is a Bright Horizons center there, I had my first child there until family circumstances changed.
Re: Dover area childcare?