Short answer: verify the state license, visit unannounced during normal hours, ask about staff turnover and ratios, trust how the room feels over how the tour sounds, and start looking months before you need the spot.
The license is the floor, not the ceiling. Florida licenses child care providers and publishes inspection histories. Checking is table stakes; what separates programs is everything the license cannot measure.
Visit when it is not staged. Any program shines during a scheduled tour. Ask to see a normal morning. Watch whether teachers are on the floor with children or managing them from chairs, and whether the room hums or shrieks.
Ask about the adults. Staff turnover is the single most honest number in child care. Children attach to caregivers, and a program that keeps its teachers is doing many other things right. Ratios, credentials and how long the director has been there all follow the same thread.
The waitlist reality. Good programs in Jacksonville fill early, especially for infants. Start touring while the need is still months away, and get on more than one list; deposits are usually modest against the cost of scrambling.
Where to look. Programs across the city are listed under Schools & Education and Kids & Family in the directory, with reviews from Jacksonville parents. Read them, then trust the visit.