In anticipation for warmer weather and the fishing season, I'm thinking about growing my own worms. I've read a little about it on the Internet and it doesn't seem like rocket science. I'm just wondering where to get suitable soil for the bin. About everything in Central Texas is either rock or that thick gooey gumbo dirt. Would potting soil from the home improvement store be suitable, or are their chemical additives in it that might be detrimental to worms?

Potting soil will kill your worms. The good brands of potting soil like Miracle Grow and Scott's usually have fertilizer included. However, organic compost without the chemicals will work great. Mix it with sharp sand from the hardware store. Clean peat moss will work. Mix in lots of organic matter and sand.

See this article.

Worms take a lot of time and care. They will curl up and die if you get them too hot, too cold, too wet, too dry or if they just do not like you. Good luck.

Also use a raised bed, say 6ft by 6ft wide by 8in tall and add grass clippings and turn the soil every few weeks, half day sun light, don't bake the soil...worms will stay where the good soil is...

Oh ya, dry out all your grass clippings in the sun till it's brown and dry before you turn it under or the nitrogen can get to high...

And I thought making plastic ones was hard.

I believe I'd try raising Water Dogs instead. Probably more demand too.

My F-I-L raised red wigglers for many years. His main compound was cow manure with plain top soil mixed in. Old bisquits and dried bread for food periodically and wet burlap on top. His beds were made from old refrigerators with locks removed and on their backs.