I raise red worms, euro crawlers, and canadian crawlers. I feed them vitamin enriched oatmeal and rice cereal. I also feed leftover vegetables that I toss in the food processor. If you want them gutloaded then pick them a day after feeding.
Depending on how many worms you have just feed them 1 time a week, as much as will dissappear in a couple days. If you notice that the food goes bad before it is finished then you have fed too much. Scoop out the uneaten food and some of the soil, then sprinkle with powdered limestone.
I also take some of the them and pickle them in garlic and powdered baby vitamins.
I haven't bought worms in well over a year and I never run out.