Yes. If you earn income selling your published works, the IRS will likely say that you are a small business owner, regardless of whether you do not have an "official business." The income you receive for the sale of your books, as well as any royalties you receive is considered self-employment income.
As a self-employed writer, you can deduct your costs of doing business from your total business income, the result of which is what will be reported as your self-employment income on your tax return.
Here is a link to a great TurboTax article with more detailed information that I hope you will find useful: Tax Tips for Freelance Writers and Self-Published Authors.