What in the world would you want to grow worms for, don't you have enough to do just tending the vegetable garden? Where will you even find time to take care of worms? Well first let me clarify you are not really growing worms your are raising them.
  The work involved is really minimal and the rewards are great.
The correct name I guess would be  vermiculture it is raising worms to be able to harvest their castings.
The castings are a great all natural fertilizer created by the worms as they compost garbage that would normally go to the landfill.
Not only is this one hundred percent organic it is one hundred percent green living as well.
If you are a fisherman this is also free bait right at your fingertips when ever the urge strikes to go off fishing.
Seriously vermiculture is starting to become an everyday activity for organic gardeners from back yard plots to big organic farms the use of worm castings and a very valuable by bi-product worm tea is growing.
While there are commercial worm farming operations the market to the small gardener for distribution is not very well developed and therefore the cost is still high due to handling and packaging.
The good news is that it is really inexpensive for anyone to start their own worm farm in the kitchen, the basement,  the garage,or backyard.
I know you are thinking in the kitchen what is he out of his mind.
The answer is no, worm farming is odorless and can be self contained in a small commercial available unit for less than fifty dollars on line and would fit easily out of site in a cabinet or broom closet.
Besides ninety percent of the compost material  will be made  up of vegetable and fruit scraps,coffee grounds, egg shells, as well as pizza boxes and cereal boxes.
Raising worms is very friendly  to the environment and does not require a lot of work but there are certain things you need to know.
Don't just go out and grab a handful of dirt and worms from the garden and throw them in the box.
There are some worms that are better than others and for the purpose of  vermiculture red wrigglers are the ones you need.
They adapt well to container living and will eat their weight in food each day.
When your purchase your worm farm it should come complete with assembly instructions as well as the How To of setting up the worms bedding and actually raising the worms.
  Worm farms can be purchased at good garden centers, garden supply stores or online.
If you are interested in starting your own worm farm I would suggest you do some research and check online for forums of worm farmers.
Here is a link with some sites Worm Farming Vermiculture.