A worm bin is nothing more than a rubbermaid tote with holes drilled in it, worms, food scraps, and newspaper/bedding. It can be as simple or complicated as you like. The worms should be going through the scraps quickly enough that the scraps shouldn't mold. Also, I like to pile a lot of newspaper shreds on top so that if anyone looks in the bin it looks like a paper recycling bin.
Here's my friend's website on vermicomposting:
http://www.wormcompostinghq.com/
My bin only has holes drilled near the top. Unlike some composters, I don't add water to my bin or moisten my bedding because my food scraps are fairly moist already and too much water can make the bin stink and the worms will evacuate the bin. My bin is on the larger side (20 gallons I think) because I compost for 4 people. My worms don't crawl out (unless they're starving - I've forgotten to feed them on occasion) unless it's moist enough to do so - but my house is on the dryer side, so the air that goes in those ventilation holes is undesirably dry and keeps them under.

The most you'll spend if you can't find any worm wranglers near you will be $30 (free shipping) for a pound of European Nightcrawlers to get you started.
Red Earth Worms - Red Worms Make Good Dirt