After you've cleaned the place to within an inch of its life, the next project is making all the repairs necessary to attract a buyer.
So, patch up the roof, touch up all the paint, repair the screens, spruce up the porch framing, and make your entry area really shine. Don't forget to water the lawn and landscape beds, and take the time to trim, mow, edge and get rid of sick or dying plants. Inside, fix the grout in the bathrooms and on tile floors, adjust any doors that need it, fix any scratches on the walls, cover any stains, and be sure to fix any plumbing problems. Remember, do what your home needs before the first buyer appears at your door.
A good agent will advise you on what needs to be done. Also, if you have friends willing to be brutally honest about what your home needs to sell, invite them to assess the fix-up needs.
There is, however, an alternative to the sweat equity you get from a total fix-up --but it carries a price. An "as-is" sale keeps you from doing all this work, but a buyer will assess about twice the price you would have paid for the repairs. Then, the buyer will deduct that amount from your asking price before making an offer.