When I use light I keep it short and simple - The way to use light in poser is the same way you use lights in real life. Two is all you will probably need (most proffessional photograhers use one subject light and on fill-in. In poser (any version) change the shadow mapping to around 0.150 and the map size to 1024 change the red channel to fit your preferences (I normally look for between 3- 5% more than the green or blue channel) this will give a soft early to mid morning light that is good for flesh tones. Having just two light mean that your rendering tends to be quicker in P4 - no difference in firefly if you check RayTrace on the lights instead of shadow maps. I've used this mapping professionally for a number of years.