Adding an RSS feed to your WordPress blog is easy. To add an RSS feed, go to your blog’s admin panel and click on the “Settings” link in the sidebar. On the “Settings” page, click on the “RSS” link. In the “RSS Feed Settings” area, enter your RSS feed URL (for example, http://www.mysite.com/feeds/123456789) and click on the “Save Settings” button.
WordPress will now check for new posts every time it polls your RSS feed and will also add a link to those posts in the “Posts” section of your blog. You can also elect to have WordPress automatically add new posts to your blog using RSS as well as Atom (another popular feed format). To do this, simply click on the “Auto Publish Posts Using RSS and Atom Links” checkbox and WordPress will take care of it for you. Finally, be sure to set up a valid RSS account so that your posts will appear in other RSS readers as well as on your WordPress blog.