My composting started out in our back yard with a chicken wire fence. It started with basic lawn debris. Grass clippings, raked leaves, etc. Than we began reading up on what else could be added to my compost (thanks @compostjunkie.com). I was pretty surprised at the number of items I could keep out of the trash and use to boost my compost. Every time I would turn the ingredients I could smell how rich the soil was getting. Than my husband found me a full fledged composter on the side of the road. It's not important how you compost, only that you do.
I never "purchase" anything for my composting. It simply diverts the whole purpose. The most important ingredient is WORMS WORMS WORMS. You don't need to go out and buy any special worms. The common Red Wiggler Earth Worm works very well. You'll find these under just about any rock, or moist shaded area in your yard. Fully mature worms will reproduce quickly. They move around the bin helping to break up the compost and speed decomposition.
The worst thing you can do is add chemicals of ANY KIND to your compost. Fertilizers, insecticides and weed killers do not belong in a natural organic environment. Chemicals transferred to a garden through compost will penetrate to crops. Crops that are potentially quite opposite of any gardeners efforts. Don't allow anyone to suggest to you that they have a "magical" product that is going to help promote your compost quicker. Your compost will work at it's own pace regardless. Just be sure to add the worms and STIR STIR STIR.
4 MORE DO'S
Lawn clippings and raked leaves are great. They decompose quickly and add a rich earthy smell to compost.
Coffee grinds and tea leaves contain very beneficial minerals and help minimize the PH levels of compost. Best of all they attract and feed those necessary worms.
Table scraps require a great deal of discretion. Adding fruits and vegetables returns vital nutrition to your compost, but you want to be sure you aren't attracting unnecessary vermin. Stay away from fruits that will overwhelm flies like orange peels that have not been cleaned.
Minimul amounts of paper that are small enough to deteriorate quickly are good also. Small napkins and notes are great, but I wouldn't toss in an entire newspaper.
4 MORE DON'TS
Meat and Bone scraps will not only spoil beyond being bearable they will attract the kind of pests YOU DON'T want in your compost like maggots.
Products containing high amounts of oil do not break down. They will only hider your efforts, and slow down any items that will decompose.
Colored or printed paper contains harmful chemicals that will not benefit the progress of your compost, or the health of your crops.
NO FECES of any kind is a debatable item. Personally, I never add animal droppings. Look at it this way...you have no idea what your dog got into that might hurt your crops.
There are two basic necessities to obtaining a successful compost. The right ingredients, and the proper care. Don't forget WORMS WORMS WORMS and STIR STIR STIR. As I always say your crops will thank you in a BIG way.