My parents have been doing humanitarian work in the Caribbean and in South America, and one of the things they have done lots of is a food initiative that has included setting people up with chicken pens and chickens for meat. They get 100 chicks at a time and they are ready to butcher in 6 weeks.
Well, I wanted to have the experience raising chickens for meat, but our approach was a little more relaxed. We purchased 11 chicks. I was DONE with having chicks in my house so I put them in the greenhouse with a brooder. It got a little warm in the day so I put some shade cloth in just in case. They devastated the lettuce growing there...and they got a few bugs there too.
My girls played with them constantly. They are such docile birds, nothing like the egg laying variety.
Our chickens didn't grow as fast as they could have as they got lots of exercise running around the yard and lived largely on sprouted wheat. I throw in all the garden extras like lettuce gone to seed and they love it.
We started butchering them at about 8 weeks and actually still have four left to go. We have learned that they cannot be left too long as they are more fragile than other chickens. When butchered ours have been 6 1/2 pounds. I was surprised at how humane it felt. They had a great life, and death didn't seem traumatic. Plucking was surprisingly easy and quick and while I wouldn't want to do 100 of them in a sitting, a few was no big deal. I would do it again.
We made a "killing cone" out of a 5 gallon bucket. It worked really well. Then we boiled water outside, dipped them in for 20 or 30 seconds and the feathers came right out.