In the beginning, it's amazing how little they eat. For the first couple months you won't want to give them much at all. And keep in mind that the cardboard is food for them, too, so it's not like they will starve if you don't have anything for a week. When I feed a bin I put about 2 pounds of food in, and I don't do that more than once a week.
I have one bin going that I haven't given food to in over a month. The worms are thriving and eating away at the cardboard.
fiwit said:A worm bin has been on my to-do list for a couple years, now.
I encourage you to go for it!