You can add an author anytime using the FrontPage console in your Web Hosting Control Panel or your Password Manager.
Your list of available authors is synchronized with the list of users in your Password Manager, including any users to whom you've granted password or FTP access to your site. You can add a user to your list of available authors in the Password Manager anytime, then use the FrontPage console to assign publishing privileges to that user. Learn how to add a new user in Password Manager.
Use the FrontPage console to add an author and assign that author publishing privileges in a subweb. When you activate FrontPage, you'll assign default FrontPage publishing privileges to one author. You'll be able to choose an existing author or add a new author. After you activate FrontPage, you can add an author to your account anytime, and assign this and other authors publishing privileges in any subweb of your site.
To add an author after you have activated FrontPage:
1. From the Create & Update tab of your Web Hosting Control Panel, click "FrontPage."

2. Click the "Manage Authors" link.

3. Click the "Add author" link in the upper-right corner of this section, above the list of assigned authors. The "Add and Assign Authors" module will appear.

4. In step 1, enter an author name and a password for that author.
5. In step 2, click the checkbox next to each subweb to which you'd like to grant this author publishing privileges (you must assign the new author to at least one subweb).
6. Choose "Add Another" to add this author and reset the module so you can add another author; or click the "Add Author" button to add only this author.

The new author(s) will appear in the list of assigned authors in the FrontPage console, as well as in the user account list in your Password Manager.
You can also add an author when you create a new subweb. Learn how.