[Beermonster]

I'm not sure if this is what you are wanting to do, but it might be

create a main forum like "General information" then scroll down you will see a box that says Act as Forum tick no, then create another forum like "information about tomatoes" and where is says Parent Forum choose the "General information" forum you have just made, then create another forum "information on apples" and do the same thing, once you have all the forums underneath "General information" create another and do the same.

Hope that's what your trying to do