Neutrik Powercon ends are made for this application. If you insist on using speakon one end is marked negative on the neutrik ends and if you don't know how to put them together there is a video on youtube.
ok yeah i figured its really basic.... I was wondering do i just buy a cord and cut it and then on the bare wire end put the powercon end. Are there power plugs (like the ones you put in a wall) that you can unscrew and put bare wire in.
in the above link, you need to use the blue jack and plug.
You could, in effect--purchase an extension power cable with a preferred length, cut it--and then attach the powerCON plug on that end.
On the board, I'm guessing you could cut the end off of a small power strip and then attach the powerCON jack and mount it on your board. You do need to have a hole big enough for the powerCON jack which is .937" wide, and two separate guide holes for the screws at approximately .945" apart (there's a PDF drawing available on Neutrik's website).