Do you ever consider how your favorite magazines and newspapers get their voice? Each is unique, the New York Times doesn't read like the Los Angeles Times, or the Telegraph. The Economist reads like no other newspaper on Earth. Vogue doesn't sound like Allure, although they cover the same ground. They read the way they do because of their style guides.
As perhaps you remember from your high school Strunk and White "The Elements of Style" a style guide is a writer's road map to good usage. Each news source, as well as many professional organizations and corporations codify how they will express themselves in print. The intent is to disguise the author's voice so that the publication speaks with one voice.
If you enjoy words, many style guides are on-line and make a great read. My favorite, perhaps due to the newspaper being my favorite read is the Economist Style Guide. The first paragraph from the Introduction explains their philosophy.
A newcomer is BuzzFeed. "Our perspective reflects that of the internet at large, which is why we hope other sites and organizations across the web will find these guidelines useful. This style guide will be updated regularly to ensure it remains relevant and responds accordingly to changes in language and common, casual usage."
The Buzzfeed style guide is wonderfully inconsistent, and covers territory adults rarely dwell but still it is an enjoyable read and your children may be impressed what you've learned.
About.com regularly publishes a list of useful on-line guides. Their criteria for a useful guide is, is it "sensible". Their list of the top English language style guides is here. They all make for fun reading.