I didn't know I filed as a "Self-employed." I have a job and am an author. I am wondering: how I can file as not "Self-employed?"

TurboTax might have chosen "self-employed" for you if you entered a 1099-Misc for work you did. If you work for someone as an employee and receive a W-2, you are not self-employed. The 1099-Misc "self-employed" income is reported on Schedule C.  You can deduct expenses to offset your income on a Schedule C but you do have to pay self-employment (SS & Medicare) taxes on your net income.  

If you are a W-2 employee, with no other income for your work as an author, then you must go to Schedule C and delete it, see below.

If you received a 1099-Misc for your work (or even if you were paid and did not receive a 1099-Misc) you are considered "self-employed".  

1. 1. Click on the down arrow next to "Tax Tools" in the black bar on the left of your screen
   2. Click on "Tools" select "Delete a Form"
   3. Scroll down to "Schedule C" and select "Delete" next to it.