Interested parties are encouraged to Google the benefits of a three-stage composting system: you'll come up with a huge, steaming pile of expert testimony, along with copious shovelfuls of plans far better than this one. There are versions out there made of pallets, wire mesh, steel paneling...
Our composter is built using the cheapest (non-treated) wood we could find, and is designed with chickens in mind: should they try to hop up on the slanted roof and jump the fence, they will fail hilariously. The front panels are removable to allow easy critter access, and the lids (roofs?) stay open for easy human intervention.
Note: I entered a Photo 'ible version of this one in the "Garden" contest: if you are so inclined (and if it remains eligible), please vote here: http://www.instructables.com/id/Chicken-Powered-Three-Stage-Compost-Bin-Photos/
Step 1: Tools, Materials
Driver/drill & bits
Of course your mileage will vary but this materials list should give you an idea:
|2"x4"||10'||6||Base, front verticals|
|1"x6" Fencing||6'||32||Back, sides, front|
|1"x1"||10'||3||Rails to hold in front panels|
We stuck with inexpensive, non-treated pine and fir.