Charles: I apologize for the delay in answering your question, but I have been out of the office. First, you have a very good resource there in the Dallas - Ft. Worth area. Your local Texas Cooperative Extension has an office in Dallas with a staff horticulturalist, Dale Groom. Dale can be reached at:Phone: 214-904-3053, Fax: 214-904-3080, Email:dalegroom@tamu.edu Second, TAMU has a great turfgrass website called "Turf Answers 4 You",
http://aggieturf.tamu.edu/./answers4you/index.htm At this site, you can find information on the proper warm season grass for your lawn. The grass selection page is excellent, I wish we had one like it in Illinois. Another page details the establishment practices that need to be done and yes, you will have to prepare the ground ahead of sod laying. As far as soil testing in Texas, once again, TAMU makes it very simple for you to get a soil test done. Go to the TAMU Soil Lab web site,
http://soiltesting.tamu.edu/ . Click on Submittal Forms, then click on the Urban Soil Form. That is all you need to do, the Urban Soil Submittal form that you will download has all the instructions and information that you will need. I hope this helps you and best wishes.