'Public' section to forum.

We are a club who has a druple based site which is basically only using the forum.

I didnt set up the site and have limited knowlage of it although i run a large invision based forum hence i got the role of looking after it!

One thing we would like to have is a single 'new members' forum which an be accessed publicly without creating an account (invite only) and im wondering how this can be done?

Daniel