Websites like PlanYourRoom and Homestyler allow users to lay out how they want to have their room, before they ever start building their home or redoing the actual room. PBTeen is one website that goes more in depth and allows you to determine a user's style of room first.
PBTeen is one of the most in-depth sites when it comes to designing a bedroom. The site takes users to a screen where users pick from dozens of decorating styles. The next step is to pick the furniture that goes with the chosen style and then arrange that furniture in order to preview what the real room looks like if they buy the furniture and patterns they selected on the site.