The square foot technique works just fine. Your plan for raised beds is a good one. I suggest killing all weeds in the area (especially any bermudagrass) with a product containing glyphosate (such as Roundup) prior to building the garden beds.
The following web site provides information on when to plant vegetables in your area. It is from Travis County but is very applicable to your area in Temple too.
This website will also be helpful:
Q&A Library Searching Tips