Advocacy Groups
HSLDA Home School Legal Defense - advocates for homeschooling.  Many member benefits including access to lawyers who focus on homeschool law and are homeschool parents.   Site has many resources including an excellent guide for homeschooling through high school.  
THSC Texas Homeschool Coalition - advocacy organization for homeschool freedom in Texas.  Site has some articles and resources for getting started.  Membership gives you legal support for homeschooling in Texas, as well as other benefits.   
Local Associations
NTHEN North Texas Home Educators Network - a network of local support groups in the North Texas area, this organization sponsors and co-sponsors various events.  Free resources include advice on getting started and a listing of local support groups.  
DCHSA Denton County Home School Association - a little closer to home, DCHSA hosts association-wide events, workshops, and commencement ceremony as well as discounted memberships in THSC and HSLDA.  Their site has resources including message board for members and listing of online class providers.  

Local Resources  

Home Educators Resource Local used curriculum store (buy/sell)
UNT Surplus Warehouse Public sale of used school furniture (desks, chairs, tables, etc.)

 

Online Resources

 

Donna Young

An incredible amount of resources, forms, guides, and references can be found on this site.  

 

Cathy Duffy

 

The most comprehensive site for curriculum reviews.