You might think about posting this on the Lawn Care Forum. There are a couple of Central Texas "Old Hands" over there.

not too late as long as you water everyday for the first week, then about every other day for the 2nd week, and just taper off slowly to about twice per week, then once per week.

i've put down sod during the summer. one summer the city did some work on the drainage system and tore through the sidewalks in the whole neighborhood, after they redid my sidewalk and curb, and laid down the new sod, i watered it in and walked on top of it over every square inch. then followed the watering regiment i mentioned above. another summer i dug up a large patch of dallis grass, and resodded with cheap st augustine.

lots of water and tamp it down so the roots are touching the soil beneath.

I second HoustonTexas123's advice. I think the main problem our turf grasses have is the amount of water they receive. If you're willing to baby them through this summer and next winter,they should do fine for you.

Yep... just keep it watered and tamped down. Its not too late.. We had ours done in June/July one year... as long as you keep it watered it will be fine.

It is a perfect timing to put down new sod.