Some things that are key in a daycare are the staff ratios.  Every state is different so I can’t tell you what they should be, but you can check your local Health Department to get that information.  Them check the day care to see if they have met that regulation.

Also, look to see if every age group has a different room.  Infants should not be sharing a room with toddlers, and so on.

Check the outdoor space too, and see how often your child will be going outside.  Ask to see what equipment your child will be using.  Ask if the toddler equipment is shared with the older kids.

If you still need to ease your mind you could ask what training the care providers have that will be watching your child.  Ask if they know CPR and First Aid, not everyone has done this, but there may be someone in the room that has.