The girlfriend's mother built one for all the gardening and flowers she does. Basically built a 3-sided box about 3 feet tall on each side out of 6x6's, then used a tarp to lay down on the ground and started tossing clipping, and any food by-products eg. eggshells, pasta, leftover fruit/veggies. She's got it in a place in the backyard that gets about 4 hours sun max during the summer. They had a problem when the rain season came the first year they made the box, so she poked a bunch of holes to allow for drainage. I don't think she had to add any worms, but after reading some other composting articles I've heard you should get a few pounds of earthworms to work it all through. If you have too much sun then you should cover the box with a tarp as well to help keep humidity up.
Hope some it helps
Hope some it helps