For Daycares and Dayschools you can do a lot of research on the Internet... Including parents comments in forums similiar to this one. What we did was call the daycares that we were interested in and asked them the same questions that we asked everyone so that we could compare the answers across the board. Feel free to ask for references as well.
Ask if you can come in and visit and 90+% of the time they are OK with that. Then you can make some "pop-in" visits and at least have had a contact person that you spoke with prior... That will help if you do an unscheduled visit. You can even bring your child into a class in a lot of places while you are visiting the school.
Ask what kind of certification they have and what kind of curriculum/format/philosophy they teach. If you don't understand it then ask them to explain the difference in their's versus another philosophy.
Churches have really great daycares as well, and you don't have to be a member of the church usually to have your child attend... and they have to be state certified just like everyone else. We ended up finding the perfect daycare for us at our church... turns out it was one of the best in the city with a long waiting list, but my father-in-law (long time church member) got us in early... still had a 2 month wait though.
Good Luck!
Also, if you or anyone else is looking for Grade Schools:
This is a nice site for basic research and stats on schools in your area. I think there's some deeper info you can get from the site like "Parent's Reviews" etc... for a one time fee. Regardless the free part is very helpful. You can see State Test Scores, Teacher Stats, Classroom sizes compared to state averages.
http://www.greatschools.net/
Here's an example of the information you can get, (This would be the school my daughter will be attending).
http://www.greatschools.net/cgi-bin/tx/other/467
There's lots of other resources out there. Information is public if they are state schools. That site also has private schools as well.
I know there's lots of other research sites on the internet out there so do a quick search. When we went looking for a place to live that had good schools we relied on 1: the internet 2: Work of mouth and 3: Real Estate Agents... they usually have LOTS of info on local school districts.
Good Luck!
Bob