I have my 5 month old at Tutor Time in Ahwatukee (Chandler & 48th St) and LOVE it! I go there everyday at lunchtime to feed and spend time with my baby girl. This also gives me a chance to see how the teachers are with the infants. They are amazing! My baby girl gets so excited when we arrive each morning and gets an ear to ear grin with she sees her teachers. It's also been great for her development as they spend lots of time playing with the children and interacting with them (tummy time, toys, sharing, etc).
I recommend you tour several places and choose the place you are most comfortable with based on your visit(s). Good luck!