Everyone can learn how to write well given enough time and the determination to learn. While it can be argued that some have that special talent with words that give them the edge, it cannot be denied that writing books and other materials is an open field for practically anyone. Perhaps this is one reason that self-publishing has become rather popular.
If you are an author who wants to get the word out about your work, one very useful resource is Marcie Brock, Book Marketing Maven. In this site, you can find tons of practical advice, which can help you in marketing your work. Topics such as building your author platform, using technology to your advantage, giving away book samples for marketing, and lots more are covered, guiding authors in the right direction.