Hi,

Other than these great suggestions I'd add some tips following the Lean Startup Methodology:
1- Write great posts about the subject of your passion (quite obvious)
2- Transform them into an ebook
3- Keep writing to make this ebook evolve and improve your reputation
4- Sell your second version of your ebook at your site
5- Then start offering video pills with more tips about your subject
6- Later, offer your readers freemium webinars.

Just some ideas.

I hope it will help you :)