Kids running everywhere? TV blaring at its loudest and the ping, ping of video games driving you insane? Meanwhile, neighbors and friends keep dropping by and your spouse is hiding in the downstairs bathroom waiting for peace to descend... Does this sound awfully familiar? If so, then it might be time to start instituting some peace across the household and to try and lead a slightly calmer life together.

[edit] Steps

Be willing to set limits and ensure that your way is followed. This is the first and most important thing that you can possibly do. This means limits as to the times, levels of noise and activity and yes, bedtimes.
Visualize a calmer home. What do you see? Write down the things that you visualize and turn them into goals to achieve in creating your calmer household. In your subconscious mind, you will unearth a true picture of the house that you'd like to be in - always keep this focus in your mind and work towards it gradually.
Sit down and write a list of the things that seem to be creating the most noise and sense of rushing in your home. These are the first things that you will target with your limits. Consider such things as when you are prepared to receive visitors, limiting the noise level of the TV and limiting to computer usage. And put a ban on running indoors for the little ones.
Write a task chart. This task chart must apply to every single member of the household and it must contain days and deadlines. The larger the job that needs tackling, the longer the timeframe you must give it in order to maintain a calm approach to it - bit by bit will get it done rather than rushing around juggling too many things at once.
Tidy the clutter away. Clutter enhances the feeling of stress, rushing and inability to think straight. The fewer bits and pieces in your pathway, the calmer you are going to feel. Not to mention the less cleaning up involved. If the kids must keep so many toys, books, and video games, make a deal with them. They can be kept in storage spaces but if they are found strewn across the floor more than 3 times in a row, they will be donated to the nearest charity store. You must mean this and you must be prepared to do it for this ultimatum to have real effect.
Clean as you create. Cooking creates less mess if you can wash items as you use them in between cooking moments. Same for anything that gets used - retrain everyone to put it back where it came from the moment it has been used. Buy storage bins or baskets with labels if this helps to encourage everyone to do the right thing.
Plan meals. If you are always wondering what to make for dinner, spend half an hour a week (Sunday evening is often a good time) to write out a plan of meals. It doesn't have to be incredibly specific or you will dull down the cooking process and spontaneity, but at least write "pasta - Mon", "steak - Tues", "pizza - Wed", "sushi - Thurs", "take-out - Fri". That way you have an idea of the main meal and can decide on the flavors and style on the night, with the main ingredients at hand.
Ask visitors to respect your limits. Inform visiting family, friends, kids, dogs, and any other guests who regularly traipse in and out of your home that closing time is whatever you set it as. In addition, feel free to set out of bounds hours, such as family lunch times on Sundays. This will enable you and your family to connect together over a special meal or activity without outside interruptions. This also includes taking the phone off the hook and closing the e-mail programs.
File it or lose it! As soon as it arrives in the post, the schoolbag or the briefcase, deal with it. Open envelopes and toss them into the recycling immediately. Read the letter, bill, or note and file it. Make bill-paying time once a week and sit down with the file and deal with it in a matter-of-fact way, one by one. If you get school notes, decide when to sit down with your child to discuss these matters, then sign them away and put back in the schoolbag, and if money is asked for, write the check there and then and put it into the schoolbag. These actions will take several minutes, but spending more time on school and child matters is more important.
Set aside calm time. At least once a week, and preferably once a day, set aside calm time for yourself in which you do nothing more than relax and shut out all that is around you. Eventually encourage other family members to join you in this. Select a special corner or room in the house and set it up just for this purpose, with soft pillows and drapes and call it something neat like "Mom's Relaxation Corner" or "Family Downtime Zone". Familiarize everyone in the house with this space as only ever being for relaxation by any member of the family at any time of the day or night. It must be away from TVs, music or other sources of noise and disruption.

[edit] Tips

Banning TV one day a week and filling the day with outdoor activities, board games or other non-electronic based and family-focused activities is a really marvelous way to create instant calm and it also creates instant family bonding.
Depending on the ages of your children, vary their chores so that they do not seem so much like chores - one week washing clothes, another week putting out the garbage, another week cleaning the bathroom, and so on. It varies the routine and also introduces them to a variety of chores that they will need to understand later in life.
If the kitchen is central gathering place, invest in a large table and some good storage cupboards for the gear that arrives with each person. Name a door for each person and ask them to always leave their loose bits and pieces and gear in the cupboard and not all over the kitchen table for instant tidiness and calm.
Read to your kids. It costs nothing to check books out of the library. Let them take turns reading a paragraph or page out loud. Get more books they can read on their own. The librarian can recommend books appropriate for their reading levels. Children too old to nap still need a little down time. Establish a daily reading time for the family, even if it's only 20 minutes. During that time, turn off the TV, computer, phones, etc.
When figuring out your meals try to make a little extra. Either include it as a side dish, entree or ingredient in another dish later in the week. If you make enough extra you can feed everyone with leftovers for a day or two and not have to really cook.
Instead of arguing with everyone about what they want to eat you should prepare healthy fare and not enter into a debate about meals. Go ahead and get it together. You'll be shocked how much time you've spend debating this, spending extra time preparing extra dishes, spending extra money on processed foods and being a short order cook for weird requests. Eventually everyone will appreciate and eat the meal but it may take time standing your ground to retrain minds.
Sugar, caffeine, high fructose corn syrup, etc. are all stimulants. Try avoiding these ingredients and you'll avoid the sugar highs as well as the sugar crashes that bring about insanity about the home.

[edit] Warnings

Don't expect immediate change. Instituting any new way of approaching things is hard for both kids and adults. Be gentle on yourself and on other family members. You are trying to change a way of life that all of you have become so used to, it has become a habit. Take it slowly and treat each new calm change as an enormous milestone.