Preventing Indexing/SEO

I have a WordPress setup in the root of my site and an SMF forum set up under a /forum/ directory. The WordPress setup is used solely for some back-end functions (because WordPress has such a wide range of great plugins available). But the forum is the site’s real function. Ideally I’d put the forum in the root for SEO, but there are reasons I really can’t do that because of the way some of my WP functions work. The WP installation’s front page is being redirected to the forum via the Quick Page/Post Redirect plugin.

I don’t want spiders on the WordPress site at all. I don’t want it indexed. And I don’t want visitors able to view it at all. I’d like to do it in a way that’s still optimized for the forum’s SEO.

Thought son how to accomplish this?