It's a pretty simple set up. An old bathtub, propped up, with an old watering can under the plug hole to catch the water (or worm juice as some people call it). It should be in a shady spot, avoiding full sun, especially mid-day glare and heat. Keep it away from your chooks, ducks and dogs, and other worm/bone predators.
Use cow or horse manure and organic matter to fill it, then place in your worms. These are a special type of worm, particularly suited to composting. Mine are called Red Wigglers. You don't need many to start off, a handful or two will do. They will multiply swiftly, and when the population level reaches peak numbers, you may find, one moonlit night, a exodus happening, with some of your beloved worms seeking new homes.
Cover the worm farm with an old blanket or carpet. Use the watering can to water the farm, then place it back under the drain hole to collect the nutrient rich excess. When the watering can is full, I tend to reuse it to water the farm again, but you can also use it to water seedlings, with fantastic results. (A word of caution, do not use on vegetable seedlings that are to be consumed in a short period of time. Especially avoid putting it on lettuce and other water rich plants.)
Don't overwater. The poor buggers drown. You also have to make sure you keep up the organic offerings, and occasionally add cow or horse manure too.
Then I sit back and leave it to my Wigglers...
Occasionally I'll turn the farm's contents and add more organic matter, but that's about it. A quick peek now and again will ascertain when the worms have finished. A strong stomach is needed at times, but let's face it, the stages of decay are part of it, and if you're squeamish, bone collecting probably isn't for you. My black swan (found by a friend on the side of the road) took almost a year for my Wigglers to breakdown. They aren't fast but they are thorough.
When I have collected my bones from the farm I rinse them (taking care to make sure all my worms have been removed from cracks and cavities first!). After rinsing I soak the bones in a weak bleach solution. It is very important to make sure the solution is WEAK, otherwise it will bleach the colour out completely and weaken the bone structure.
I don't usually bleach bones that have been exposed to the elements. The natural colours: soft green hues and varying shades, have an inherent beauty that I take care not to alter.
I sort my bones into sizes and types, according to my needs. I'm happiest when both my wax and bone supply are well stocked. You never know what you may need midway through a sculpture.
(A final note: some local councils don't allow the removal of road kill. Others use noxious poisons on the road verges. I never pick up roadkill or bones from such areas, as I have no wish to use toxic chemicals in my sculptures.)