For the LEDs run common 12V and Ground lines either to an arcade PSU if one is in the cabinet (Looks like what is in the picture on the link I sent.
Or if using a PC PSU, take them both from a power connector for hard-drive or CD-ROM/DVD, Yellow is +12V, Black is ground.
As for the buttons, are you using JAMMA or another interface, ie IPAC ? Usual method is to connect all the COM blades together as a common Ground connection and connect the NO (Normally Open) blades to the switch inputs.
Hope this helps
> Thanks - at least that shows me where to hook up the 12v and grounds to the buttons
> so that is big progress. I can find a ground with no problem but anyone have any
> advice on where to splice into 12v? I did not build the thing so I am not too sure...
> Also, does it matter which blade goes to the buttons to either side?