Online auctions are marvelous things; bringing people together from all over the world, to sell things amongst themselves, and take a cut off the top. Everyone has something that someone else wants, so this idea is golden - and we all know how well Ebay is doing. So now you want to build an auction, but don't know where to start? There is a lot of thought and engineering that goes into such a development, so you'll need to start out on the right foot.