L.H.
I live in south Arlington, too, with our first baby due in October. I'm starting to do the same type of investigating. I've only looked at this site once, but it looks like it will be helpful. I have co-workers who found their childcare this way.
http://www.dfps.state.tx.us/Child_Care/Search_Texas_Child...
If I come across anything else, I'll let you know. Good luck and congratulations. :)