Vacuum the book with a soft brush. Turn the book upside down while cleaning the edges so that the dust falls downward, not back into the pages.
Clean grease or oily marks with a dry paper towel. For inside smudges place the paper towel between the dirty pages and close the book. Place a weight on top. Allow the paper towel to absorb at least 3 days before removing.
Press lightly with a white plastic eraser to remove pencil marks. Always erase toward the side of the page not back and forth. Vacuum the page afterwards.
Spray glass cleaner on a paper towel to clean a glossy dust jacket. Use only enough to dampen the towel then gently wipe the jacket.
Use a dry cleaning pad to clean non-glossy jackets. Go to your local arts and crafts store for this item. Pour a small amount of the cleaner from the bag onto the surface and finger rub the material lightly on the marks. This also works with certain pencil marks.
Take extra care in cleaning cloth bound books. It's tricky and can cause further unsightly markings. Absorene, stocked by art and craft stores, is recommended. It's malleable. Lightly rub it across the book's covers then vacuum as necessary.