Recent changes in Texas law place some stringent requirements on the seller that for your own sake you need to be aware of.
In the worst case scenario, if you fail to comply with Texas law, you will forfeit back to the buyer all monies collected from him since the start of the contract. Basically, this can bankrupt you.

You need to consult with an attorney, period. Realtors are not allowed to write a contract for deed, because of their complexity and the possible dire consequences for non-compliance.

You can look up the statutes and read them, but the contract itself should be written by an attorney.
http://www.statutes.legis.state.tx.us/SOTWDocs/PR/htm/PR.5.htm and pay particular attention to SUBCHAPTER D. EXECUTORY CONTRACT FOR CONVEYANCE Sec. 5.062 and those following such as 5.069 and 5.077, where your annual requirements are described.

Good luck.

Monique you need a good real estate attorney to make sure that the contract has all the terms and conditions that are needed in your state. That attorney can then file the land contract with the county recorder.