Subscribe via Email Widget (Genesis eNews Extended)
To add a subscribe via email widget to your sidebar, download and activate the Genesis Enews Extended plugin.
Under Appearance > Widgets, drag the Genesis Enews Extended widget to the Primary Sidebar or if your theme has a designated widget area, add it there.
Configure the settings per the plugin instructions. Or, if you don't have an email list, use the JetPack plugin via this FAQ (link).
If you are using MailChimp, check out our blog "How to Add MailChimp to Genesis eNews Extended with WordPress."