This is my area!!!!!!(qualified Early childhood teacher).
1) Make sure it is accredited this is the first major thing to look out for, because if it is accredited this means they have certain guidlines and procedures that the centre has to stick with!
2)Go for a visit and see what the atmosphere is like. See how children react to teachers, the routine and general play, at every centre there is always one child upset, see how the teachers treat this child (i.e. do they leave him in a corner to get over it by himself or is someone there comforting him).
3) Look for centre policies and see what they want for the children.
4) Ask if they have portfolios that they put together of the childrens artworks so that you get to keep at the end of the year. See if they do parent/ teacher interviews, you will know if they are approachable.
5) It is always good to stay with your child for the first 2 visits for just an hour so that your child knows it is a happy and safe environment.
6)Get to know who the primary caregiver will be of your child.
7)Check to see resources in the centre a good- not broken or old.
Hope this will help.....