Build site with integrated forum?

Hi, I want to build a site that has an integrated forum.

but I dont know where to start.
would you please kindly give some suggestions?


Install a forum, then make web site using any programming language, use forums users table for login.

vbulletin 4 ships with a cms system.

as I know, vbulletin is not free.

due to limited budget, I can only afford free ones…