The first step in preparing the exterior of your house - a buyer's first introduction to it -- is to take a clear-headed look at the house from the street. Stand at the curb and look at your house as a buyer might. What stands out and catches your eye? The beautiful landscaping and new roof? Or does something else strike you? The faded exterior paint? The ruts in the driveway? The two missing shutters? Remember, this is how your home will "introduce" itself to a potential buyer. If the appeal isn't there, they will likely move on to the next available house, no matter how beautiful the interior of your house may be!
If you need major improvements or renovations, do them before you put it on the market. The average buyer simply does not have the "vision" to see the job done if you plan on doing the improvements prior to the buyer taking possession. If you are attempting to sell your house as a "fixer-upper" be aware that even though many buyers say that this is what they want, when confronted with the prospect of actually buying one, they often run for the hills!