As a general rule, Texas Rules of Civil Procedure Rule 502.4(b) states that a defendant in a small claims or debt claim case is entitled to be sued in one of the following venues:
(1) the county and precinct where the defendant resides;
(2) the county and precinct where the incident, or the majority of incidents, that gave rise to the claim occurred;
(3) the county and precinct where the contract or agreement, if any, that gave rise to the claim was to be performed; or
(4) the county and precinct where the property is located, in a suit to recover personal property.
Subsection (c) of that Rule goes on to state that if the defendant is out-of-state or if their residence is unknown, "the plaintiff may file the suit in the county and precinct where the plaintiff resides".
E-filing is a way of filing court documents electronically, without having to send in paper copies to the clerk's office. Texas's eFileTexas.gov site uses guided interviews to help you create your forms. The website will ask you certain questions and use your answers to build your forms. The e-filing website is free to use, though you may still be required to pay standard filing fees with the court.
Below are links to the justice courts for some of Texas' most populous counties. Most of the websites listed will have you select which precinct in order to locate additional filing information and downloadable print forms (if available).