If you're feeling uneasy about something you've typed, check it. As you're interviewing, make a mark when someone gives you an important fact so that when you have one last question you can find the marks and then follow up to make sure you are clear. Make a list of facts to check as you write your story so you don't forget to go back and check important things when you're done. Web sites are notorious sources of misinformation. Anyone can put up a Web site, but that doesn't make that person a reliable source.
Numbers Check all calculations with a calculator.
In other words, do the math. Editing If you're reading a page proof, check break lines to make sure they're correct, double check captions, make sure the right caption is with the right photo. If you make ANY changes in content, be sure to run them by the reporter or the assignment editor. Even if you don't have time to ask while editing a story, flash the change by the reporter or editor in a message. Always find the first reference to a person in copy.