I'm a total noob as far a SEO goes, so please forgive my question if it seems dumb.

I have a site that's built in phpfox. Integrated into phpfox is a vbulletin forum. Visitors can access the forum and read the posts without registering, but cannot post without doing so.

Do I need to do anything else so the googlebot can index the forum posts?

as far as users (and bots) can read posts without logging in there is no problem

You don't have anything to worry about. If guests can see the posts then bots can.