Photographer Zack Arias is mostly a commercial and editorial photographer these days (while wanting to do personal portraits) and many of his most famous photos are on location. But he took the time to create two videos on Dedpixel to school you on using a white seamless background. The biggest rule of all is that you need more than one light typically. At least one light should hit your subject and at least one should hit the background, but the one hitting the background needs to be exposed one top more powerful than your main light.
He also shows things like how a scene can be lit light at a time. The videos are after the jump, and well worth your time to check out.
Via ISO 1200