Do it because you like to do it. If you start writing because you need the money, or the publicity it will become very fast to a task that you will hate. Writing should start like any other art, from with-in. Do it because it makes you feel better, and if it does make you feel better it cannot be bad writing. To transfer a story to become a book it is another level of writing. It is long, hard and expensive task. This part or writing is not for everyone.