Homebrew PCBs

hi Group I am about to start to make a PCB board on a mill/engraver I 
have a dxf file how do one make it in to a cam program I tried to get 
the book from John Kleinbauer In this group but he will not sell to 
us Canadains so i have to find all the info my self ,can some one 
point me in the right place .

Brew