Subscribe2 - Wordpress
From Help Wiki
Subscribe2 is a plugin that, once activated, will allow your readers to receive an email notification whenever a new post is published to the site.
- Activate the Subscibe2 plugin in your plugins panel
- Create a new page (probably called something like "Subscribe"
- Click the S2 icon that should now appear in your rich text editing bar.
That's it and you should be up an running. If you're interested in changing some of the default behaviors of the plugin, go to Tools > Subscribers and change your Subscriber settings here.