Just like any writer or journalist, it is important that you make sure that the final work you create is your own. Give it your own "voice", keeping the facts while ensuring that you are not wholesale copying another's work. Failure to do so could constitute copyright infringement. A great way to know whether or not you've made your articles uniquely your own is to run them through CopyScape.com before using them on your site or submitting them to free article sites.