• Goodreads: not recommended unless your publisher is doing it
• Book bloggers or literary sites: The more focused on your genre, category, or theme, the better. Get a media kit that offers audience reach numbers and indication of audience interests.
• Mainstream media (e.g., New York Times): not recommended unless your publisher is paying
• Review outlets (Kirkus Indie, Booklife, etc): not recommended
• Learn about what sort of book ads work from Shelf Awareness.