Yeah, the worm bins are great and are a piece of cake to maintain. I highly recommend starting one (or two, or three) for yourself. You can order the worms from here:
http://unclejimswormfarm.com/
2,000 red wigglers for $29.95 + shipping. Great deal IMO.
Here's what you do: Go to Home Depot and pick yourself up a 10-15 gallon rubbermaid tote. You can drill some 1/4" holes around the bin and lid, or you can rig it up like I did by cutting out the center portion of the lid and taping/gluing some mesh or screen over it. Here's a pic of my bins ....
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All you need to do once you've set the bins up is put some bedding in it, add some food, then add your worms. For bedding I like to use a combination of coco coir, old dry leaves from the back yard, a handful of used soil, and a bit of shredded newspaper or cardboard. The corrugated cardboard is nice to have in there because they seem to like to lay cocoons in it. As for food, pretty much any kitchen scrap is good aside from garlic, onions, meat, dairy, citrus fruits, and anything oily like salad dressing. I use a ton of fruits, veggies, coffee grounds, roasted egg shells, tea bags, fan leaves from my marijuana garden, etc. I also like to add some dry organic amendments that I use to make my soil. They are voracious eaters and will eat as much as their body weight (1,000 worms is roughly a pound) every day! What you're left with is the highest quality worm castings for free made out of stuff that you would otherwise throw in the trash. If you have any specific questions beyond this info feel free to pm me.
From these castings I amend my soil, top dress current plants, and make compost teas (AACT's). Per the advice of a very knowledgeable grower, I keep my compost tea simple. I use only worm castings and molasses. Basically 1-2 cups of castings and 4 tablespoons of organic molasses to 4 gallons of water, bubbled for 36-48 hours then applied as a soil drench. I am basically adding a food stock (molasses) to the tea and allowing the microbes present in my castings to rapidly multiply by up to 10,000x during the 48 hour brew, then adding to my soil.
The rock dusts can be ordered online, picked up a garden supply center, or you can check with a local rock quarry to see if they would be willing to hook you up with some. I get mine for free at a local quarry. Simply put, rock dusts serve two purposes: Trace minerals, and improving the CEC of your soil. IOW, it improves your soils ability to hold on to plant available nutrients that would otherwise be washed through your medium as runoff.
they are good to have on hand. I have saved myself a considerable amount of $ I would put out just for worm castings alone. So to me its well worth throwing a handful of old coffee grounds & shredded newspaper in there for them on occasion. 
they eat it up..
