Ongoing Care and Cleaning
Once you're set up and have your flock, you'll need to have a somewhat regular plan for taking care of them.
Cleaning The Coop
Regardless of the specific type of coop you have (permanent or portable), you need to have a plan for keeping it clean. Not only is it more pleasant to be around, but a clean coop will also have fewer parasites and diseases.
Some cleaning chores are more frequent than others, so it's not like you have to spend every weekend scrubbing out your coop. Every day, you should check the coop and ensure the water and food supply is in good order. Add fresh water or food if necessary, and clean the containers if they are dirty. You don't have to scrub them every time they get a speck of dirt on them, so use your own judgment.
Every weekend, clean up the bedding. There are a few ways to approach this and you can adjust it to suit your own situation. The best idea is to rake out the most soiled bedding, which is usually under the roosts and add a new layer of clean bedding on top. It's not necessary to scrape it all down right to the floor every week. Your old bedding can go into your compost bin.
Once a month, take the waterers out of the coop and scrub them with a weak bleach solution. Rinse them very well, and let them air out before putting them back into your chicken coop.
You can save the big cleaning chores for twice a year, roughly late fall and mid-spring work well though you can time it for your own climate. Getting the coop cleaned out right before the cold winter sets in, and then again when the spring soils have warmed and dried work best (both for your chickens, and for the person doing the chores). At these times, you really should get rid of all the bedding, and give the inside of the coop an actual wash with water or a disinfectant solution. Dilute bleach can be used, but only if you can leave the coop open and empty of chickens long enough to let it all dry and air out.
All of these schedule suggestions will depend very heavily on the number of chickens you are keeping. A coop with only 4 chickens will need a different amount of cleaning than one with 12.
Obviously, if you see any damage or wear around your coop you'll want to fix it as soon as possible. During your weekly clean-up, also give the coop a look over to see if there is anything that needs fixing.
See if there are any holes in the window screens, or if any screen edges have come loose from the window frames. Give each one a gentle push to make sure. When a corner is loose, it may not be immediately visible because it doesn't look like a hole. Also check if anything has been chewing around the vent openings.
Push the bedding away from the corners where the walls meet the floor, to see if any mice have tunneled their way into the coop. Patch them up with a little sheet metal (even a flattened soda can will do).
Periodically you should also check inside the coop after a heavy rain, to see if any leaks have developed in the roof. Check for odd patches of wet bedding that would indicate a leak and patch it immediately. A chicken coop is damp enough as it is without rain coming in.
You should also turn your attention from the coop to your flock itself. If you have the time, you should take a look over all your chickens each time you are there to collect the eggs. If not, try to inspect your birds at least once a week to see if any of them are acting lethargic or show any other possible symptoms of disease, injury or illness.
Skittish chickens may not permit too much close contact with you but you should to your best to get near them. The sooner you detect a problem, the more treatable it will usually be.
Once you have regularly laying hens, someone will have to check for eggs pretty much every day. Unfertilized eggs cannot stay outdoors for very long before they start to go bad, especially during hot summer weather. A daily check will make sure your eggs go into the fridge right away. When it's hot, it wouldn't hurt to even check twice so no eggs go to waste. And conversely, you can usually check a little less frequently during the winter. Not only is the temperature better for preserving the eggs, but your hens will be laying fewer eggs unless you have added light in their coop.
Take a Vacation?
A little side topic that needs to be mentioned when it comes to the ongoing care of your chicken flock, is what happens when you can't be home. Like with any pets, you will have to make allowances for their care when you plan any kind of holiday away from home. Just remember that a neighbor who doesn't mind feeding your cat may not be as agreeable when faced with your horde of clucking and flapping birds. Don't leave it until the last minute to arrange with someone, in case you have to ask several people.
For an overnight trip, you really only need someone to herd the chickens back into their pen and secure the door so they will be safe and then let them back out again in the morning. As long as you have filled your feeder and waterer, they should be fine until you return. For longer absences, your chicken-helper will also need to provide more water or food as well as regular letting in/out of the coop. Don't forget to tell them to collect the eggs, which usually makes a good bargaining chip if you let the person keep them.
If you really have no one to help you, you should be able to manage an overnight trip without any assistance. Just lock up the chickens with plenty of food and water before you leave. One day without access to their outdoor pen won't do them any harm.
The one thing you should not do is leave them alone, with the door open to the outside pen. It is not safe during the night even if the chickens are bright enough to go back inside to roost. There is a good chance you can come home to fewer chickens than you started with. They need to be safe and secure when no one is home.