Have you tried looking for your family on LDS Family Search? See the URL below. It's also worth having a look on the Rootsweb project for Texas. They have lots of birth/death/census information for each county. I'm not sure which county Hale Center is in, but it'll be there, I'm sure.
My Guerrero family come from San Marcos, but I don't know where before that. I think using the internet for research is a good start, but if you can do some research in person, that's (from what I've heard) the best way.