I used BabyCenter a number of years back to get a list of questions to ask. The site has changed a bit but I looks like they still have good information.
http://www.babycenter.com/childcare/
some suggestions. THere are immediate type of questions and longer term types of questions. You want to think about whether this is where you want you child to be at 3 or 4 for pre-school. That doesn't mean that you can't change your mind, but looking ahead now may prevent you from having to move your child from someplace he becomes comfortable with.
Immediate questions:
Licensing (they probably are but verify)
Teachers
-what are the backgrounds/educations
-how long have the one's that will be in the baby room been around
-what is the average for other teachers
Customer Base
-How long does their average customer stay
-Can you talk to some other parents
-Do they do any parent surveys or anything to get input
-Do they have conferences with you the parent.
First Aid certifications/safety things:
-CPR
-Fire Drills
-Safety of accessing the building (how do they protect the kids)
-Rules for signing your child out (back-up relatives, etc.)
Food
-Do they provide breakfast and/or lunch, if yes what do they serve
-Snacks? - Do the give them and what are they
Fundraisers -Do the make you participate in any sales
Rules/Policies
-Biting and other behavoir
-Will they notify you if your child is hurt by another child
Longer Term questions:
Ask about the pre-school program, acedemics, etc.
Field trips - do they take any, when do they start, do you pay extra for them
Summer Programs - do they have any, is it a "camp", do they do different things then during the regular year.