Here you find how build a "Spot light" (and you can load it some yet ready made) http://www.suplugins.com/index.php?p=page&page_id=spotlight
(all is building in Google SKetchup of course)

And for "Omni light" (load)
Beginning tutorial / Omni Light
http://www.su-podium.com/Podium15Help/Default.htm

And yes it is the more easy render I had never seen !
A terrific simple prog :)