-[Clicks and Clocks](http://clicksclocks.de/tag/busboard)
[This article](http://metro-modular.com/index.php/captain-s-blog/33-why-busboards-matter) explains busboards. Their GND should be connected in a [star topology](http://www.geofex.com/article_folders/stargnd/stargnd.htm) and for the other supply voltages it doesn't hurt to cable them the same way.