Making and Designing a Forum

You shouldn't think about membership options and bring in money until you're completely done with your website. You have to convince people to sign up BEFORE you ask them for money... which is already hard enough if you don't know what you're doing.

Hire a programmer and get a theme built along with some plugins that nobody else has to offer. Hire a few writers/bloggers to research topics and write content for your site on the daily. Study SEO and put some money into a marketing campaign.