Wallpaper is bad, don't do wallpaper. Go to your local Home Depot and pick up some beige swatches.
You can get really nice wallpaper that works well if you have a keen eye for design, but it needs a knowledgable hand and will probably be very expensive.
You should also avoid wallpapering an entire room, unless you are happy living in a house that looks like it was designed in the Sims.