It is not that hard, but a common sense approach and a bit of planning ahead makes it a much more successful venture.... coops need to be kept dry and ventilated but not breezy, don't go cheap on food, quality food in the right amounts is needed for the best chance at good health and fighting off illnesses and injuries, prepare your coop and run based on the normal predators in your area... If you short cut to save expenses or time you may have trouble later down the road. No coop has to be Fort Knox or a Taj Mahal, but it does need a few basics.
Take the time to do some research into basic chicken health issues, many times the best treatment is preventative care to begin with! I spent a lot of time reading magazines, books and these boards before we got our birds and the learning never stops. It may sound intimidating but chickens are very hardy and forgiving critters if you just cover the basics. They are well worth the effort in companionship, eggs, meat and pest control too!