Runtime DNA has a gazillion free light sets, but you'd be better off learning how to do this stuff yourself. If you know what looks bad, you're half way to what looks right. The fact is, Poser's lights aren't top notch by modern standards and you have to work hard to fool the eye. Of course you could buy Vue (or Carrara 6) and have a go at the Global Illumination and Radiosity presets to learn what a modern renderer is capable of.

Download my free stuff here: http://www.renderosity.com/homepage.php?page=2&userid=323368