How do I make the Help, Support and FAQ accesable with login only?

I have set up the site http://problog.no/
I have placed the Help, Support and FAQ as a menutag ant it has this address http://support.problog.no/
How do I make the FAQ only accessible after loging in? Can I set it to be the same username and password as on the mainpage http://problog.no/ ? Or du I have to use a new registration for those who want to access it?