I just made a worm bin out of some plywood. For a vertical worm composter, just make two boxes. The bottom box will have holes and screens over the holes and no top. The top bin will have a hardware cloth bottom and a removable top. Put your bedding down in the lower bin (leaves, newspapers, etc), put a balance of nitrogen food (greens) and carbon (dead leaves and other dry stuff). A balanced diet will produce no foul odors. When the worms have finished eating all their food in the bottom, about 4-6 weeks later, put food in the top bin. Since they can crawl through the netting in the second level box, they will all migrate. Look for about 2000 worms (2lbs). 2 lbs. of worms can potentially eat 1 lbs. of food per day, although it's best to let them eat all their food before feeding again. Buy red wigglers or wrigglers, not nightcrawlers.