Setting an email subscription field call-to-action will allow users to subscribe to your mailing list from the homepage.
To do that:
1. Open the HOMEPAGE tab in your sidebar
2. Open the TEMPLATES tab
3. Click on Customize
4. Click on the Call-to-Action section to get a drop-down list
5. Select Mailing List Field
6. Click on Settings next to the Mailing List Field in order to change the item's position.
Please note that this option is available for premium websites only.