A couple of websites you can find shows is: www.craftlister.com , also www.festivalnet.com . I know there are a few others, but I can't think of them off the top of my head! There is also a really good magazine listing shows all over TX: "Where It's At". I think their website is www.whereitsatmagazine.com
My parents organize & promote really high quality arts & crafts shows--mostly very nice handmade items. Their website is www.shoppingseasons.com . They have one show left this year at the Garland Special Events Center which is just off the George Bush Turnpike. They do charge admission to their shows (usually $3 or $4), but the admission always benefits a local charity or non-profit.
Hope that helps!