I wrote an Instructable making stacking bins outta old buckets. They aren't completely bug free, but the bugs stay mostly contained. Easy harvest and cheap as it can get. The worms sort themselves out of the finished product, and it's size can vary from small to huge if you like as well.

I made my worm bin out of a sheet of old plywood and 3 2x4's . My final project was a box 2'x4'x2' and it only cost me $4 to make (nails , screws, and hinges). There are several good ideas on the site that I based my project off of.

You really dont have to turn the worm compost. As the worms burrow they open up channels for air flow. I have not had any issues with rats or mice in the worm-a rater. Now the pond and bird feeders on the other hand really attract them. The only real issue I have had with the worms has been the compost getting too hot.

Try the 55 gallon drum project, or one of the other composting Instructables.