This is free software, called pbpBB, available from
http://www.phpbb.com/.
If you are running from an ISP server, many of them offer Fantastico which offers automatic installation and set up of the forum.
Getting phpBB installed and running is very easy. The management panels are straightforward and the documentation is good.
Adding your own logo to the header is also fairly straightforward. You swap out the picture, keeping the same name.
Adding more bells and whistles becomes more complex and will take time to learn the system. There is a good forum at the phpBB website where lots of volunteers can answer questions.
