A house, a feeder, a drinker, a bin for their feed, bedding.
All the rest is fine-tuning. I also keep in Poultry Spice and every 6 months I buy Marriage's layers pellets which have Flubenvet in, to worm them. Feed it for a week, instead of the normal stuff, job done.
You asked about a size of area for about 6 chooks. It depends a lot on what your land is like (how wet) and whether they're going to be permanently in there or let out when you're about. If very wet, they'll kill off the grass quickly and it'll be muddy thereafter.
The nicest chook set-up I ever saw had the houses in between two grassed pens. The birds in each bit were alternated between the two pens.
When I used to keep 4 chooks in a town garden, in a previous life

, I had a fenced area about 12ft x 10ft. About half had paving slabs down, this is where the house was and where I put the food and water. The rest was bare soil which I dug over every week - this kept it sweet and unearthed the many worms, much to my hen's delight

Don't be daunted - unlike some other, woolly, livestock I could mention, chooks seem to aim to be happy and healthy
