The Texas Legislature Online posts the Texas Constitution, statutory code, bills, etc. The Secretary of State posts the Administrative Code. The Secretary of State also posts the Texas Register back six months; the Register is archived back to 1991 by the University of North Texas. For older issues, call the Register at (800) 226-7199.
For more links to free online legal materials, try FindLaw. Texas primary legal materials are also available from Lexis and Westlaw. Versuslaw has cases.
Google Scholar has free cases law back to 1950.
Supreme and appellate court cases are published in West's South Western Reporter.
Texas session laws are published in Vernon's Texas Session Law Service (West). Texas session laws from 1846 to 1921 are posted as part of Gammel's The Laws of Texas by the Univerity of North Texas Library. The HeinOnline session law collection has Texas session laws from 1824 to about a year back.
To check on the status of a pending bill, call the Legislative Reference Library from outside Austin at 877-824-7038 or (in Austin) 800-463-2182 or (either way) 512-463-2182.
Businesses: You can look up business registrations and retrieve filings through SOS Direct. The database covers:
Limited Liability Companies
Limited Liability Partnerships
Foreign and State Financial Institutions
Uniform Unincorporated Nonprofit Associations
Probate Code filings by Foreign Corporate Fiduciaries
UCC Financing Statements
Citations: The Texas Legislative History & Administrative Agency Citation Guide provides Texas-specific citation forms.
Corporations: For information about Texas corporations, call the Texas Secretary of State's Corporate Information Line (512-463-5555).
Docket Sheets and Case Files: iDocket.com provides docket sheets for many Texas courts. Also check the court web site. For additional sources, see the separate "Docket Sheets" entry.
Pleadings, briefs and other documents in the case file may be available electronically through the court web site or through one of the commercial services listed in the "Docket Sheets" entry. Alternatively, you may be able to call the court to order a PDF, or you may be able to order documents through the court web site (e.g., Brazoria County Distric Court).
Legal Encyclopedias and Research Guides: West publishes Texas Jurisprudence, which is available in print, on Westlaw (TXJUR) and on Lexis (TEX;TXJUR). For a discussion of Texas legal materials, see Researching Texas Law (William S. Hein & Co.) by Brandon Quarles and Matthew Cordon.
Legislative History: The Texas Legislative Reference Library posts an excellent explanation of how to compile a Legislative History for a Texas bill (www.lrl.state.tx.us/legis), including a list of agencies that compile Texas Legislative Histories for a fee. Legislative Intent: The main sources for discerning legislative intent are tape recording of House and Senate proceedings that are available back to 1973. For questions, call the Legislative Reference Library (512-463-1252).
Libraries: For questions about Texas legal materials, copies and/or inter-library loan, try calling the Texas State Law Library (512-463-1722), the University of Texas at Austin law library (512-471-7726) and/or the Texas A&M University law library (713-646-1711).
Taxes: Texas taxes are handled by the Texas Controller's Office (512-464-4000). I have found the staff helpful and courteous.
Transcripts: Westlaw has transcripts of oral arguments from the Supreme Court of Texas, Court of Criminal Appeals of Texas and Court of Appeals of Texas, 8th District (TX-ORALARG), as well as selected trial transcripts filed in state and federal courts (TX-TRNSCRPTS-ALL).