One of the best Weed Identification resources available in the United States is a 32 page publication written by Penn State Extension Horticulture Specialists. The line drawings of the many different types of weeds are exceptional. Here is the link for this publication – Weed Identification
Understand that approved and available pesticides will vary in Texas. You can call your County Extension Office to discuss options in your area. Individual retailers may or may not carry all approved treatments.
NOTE: The Weed Management in Turf publication is provided in Portable Document Format (PDF). You will need to have the free Adobe Reader installed on your computer to download, view and print this resource. If you do not have Adobe Reader, here is a link for the free download and quick installation: Adobe Reader