The RSS widget is designed to add an outside to your blog. Your theme probably has an RSS button somewhere on your blog page that your readers can use to subscribe. If for some reason your theme has no RSS buttons built into it, you can create them by adding code to your sidebar in the theme editor.
For Your Feed:
<li>
<a href="<?php bloginfo('rss2_url'); ?>" title="<?php _e('Syndicate this site using RSS'); ?>"><?php _e('<abbr title="Really Simple Syndication">RSS</abbr>'); ?></a>
</li>
For Your Comments:
<li>
<a href="<?php bloginfo('comments_rss2_url'); ?>" title="<?php _e('The latest comments to all posts in RSS'); ?>"><?php _e('Comments <abbr title="Really Simple Syndication">RSS</abbr>'); ?></a>
</li>
Once you have a link, your readers can use it to subscribe.
Hope this helps.
