I strongly encourage you to hire an attorney. What you are trying to do is just not easy!
The Harris County Law Library is available to the public. The law schools also have law libraries. I don't know if they are available to the public. You would have to call and see if they would let you use them.
You can go to any law library and look for books that contain information on preparing discovery. Please only read about "discovery" in the State of Texas. Please don't read about discovery in federal court. Divorce is a state issue. There are many books. There is a set of books called the TX FAMILY PRACTICE MANUAL that family law attorneys use. You will immediately notice that discovery is not easy. There is not a form that you can just download and print out -- no such thing exists.
You will quickly determine that attorneys really to "practice" law. They "craft" documents. There is not one document out there that every attorney uses. There are master forms. But for each divorce an attorney must develop the discovery for that particular case. It requires thought and strategy. This is what an attorney gets paid for!
This is why I recommend that people hire an experienced family law attorney. When an attorney gets out of law school they know the law but they don't know how to practice law! They have to learn how to apply what they have learned.
There are the Texas Rules of Evidence plus Harris County local rules of court.
For example, when you issue interrogatories, you can only issue a certain number of them. Why? Because you cannot overwhelm the other side. If necessary, you can issue more than one set of interrogatories. Again, you must follow all of the applicable rules. (All of this is confusing to attorneys too!)
Many years ago, we were required to send a copy of everything to the court's file. The court's got tired of their files getting so thick and heavy. Now you no longer have to send them a copy of everything.
If you violate these rules, bad things can happen to you, such as, the judge strike your pleadings (and that is very, very serious) or order you to pay your spouse's attorney fees. If you don't understand what "striking" your pleadings means, that means you really need an attorney.
Even though it is a remote possibility, you could be looking at contempt by the court, that includes monetary fines and/or jail time. Yes, it can happen!
I don't try to do my own dental work and I don't do my own plumbing work, I hire someone that knows what they are doing. A plumber once told me that he "loved" guys who tried to fix their own plumbing and the made a lot of money off the "do it yourself" guys, he charged them 3x a much because they made a huge mess! He admditted the handy men kept him in business!
Remember, if you make a mess then you are going to have to pay a lot more in legal fees to an experienced attorney to "fix the mess" you are creating. Plus, you might make a bad impression on the Judge and that is not a good idea!
Please don't buy anything at an office supply store, sold on the radio, t.v. or internet by a company outside of the State of Texas! There kits were not designed by a Texas attorney. They do not comply with Texas laws.
Plus, please do not call 411 and ask for "legal aide". That company is a for profit company that has a horrible BBB rating. The man changes his name every few months and has lots of unpaid claims against him. It's a total rip-off.
If you need a referral, call or email me at firstname.lastname@example.org.