How do you earn from starting a forum? What is a grand?

You earn from targeted adsense clicks from forums. Build it based on a high PPC topic. Stock it with highly targeted and highly researched paid forum posts. Recruit from existing social networking and email comunity sites.

Adsense and YPN do real well with Forums. Your users generate your content and search engines index it. You may have a forum about a specific car model but if you have an off topic forum where members can talk about anything you can start getting traffic based on those threads through the search engines.