Tracey, the key to being organized is to have a clear vision for the space then set some limits and establish routines. What you are doing with your papers (cluttering your countertops and the kitchen table), your kids are doing with their toys (cluttering the family room).
First, you need to what you want from each room—family, living and kitchen. Check out this room function chart.
Then, establish the limits for each room: Where do you place your paperwork—a file tray, box, container or on a shelf? Where do the kids place their toys—bins that are large enough accommodate what they play with? Then, establish and stick to routines. Where do you put your mail/paperwork when it comes into the house? Throwing it onto the kitchen counter or table to deal with later is not an option here! Alternatively, where do the kids put their toys at the end of the end of the day?
Things don't put themselves away, and your kids won't learn organization automatically, especially is you're not modeling the behavior you want. — Peter