S.H.
Contact the Texas A&M Extension Center in Richardson, (Cambell Road I think-it's in the phone book under county blue pages) They have an entire gardening program you can go through or just helpful info (at no charge).
Local gardening centers (Calloways) will be helpful, but will charge you for each little thing. And buy the book the Texas Gardener.
You should have your soil tested to know what you need in the way of fertilizers, soil enhancements, etc.
Best luck and happy planting. Remember choose drought resistant plants, or you'll be paying a huge water bill to keep it alive in the summer.
Susan in Dallas