CherishR, I am also in North Texas. You will need to get a Sales Tax & Use Permit, as administrative services are taxable in Texas. It is real easy, you can do it online and you'll get your Tax ID# immediately, then they mail you a certificate within a couple of weeks. Here is the link,
http://www.window.state.tx.us/taxpermit/. They will ask you for a NAICS code, I used 561410, which is all document preparation services. There is a link to look up other codes, but that one covers the majority of my services.
Hope this helps! If you have other questions, just contact me.