Below are some tips from the removal of stains from hard wood floors based upon those types of different stains.
One very IMPORTANT thought to express is to NEVER mix ammonia and chorine bleach. Don't forget it.

For removing alcoholic beverages rub a clean cloth that is dampened with that of rubbing alcohol.

For removing blood stains from your floors, use cold water before using any detergent, and if the blood stain has dried too much, create a solution of ammonia and that of cold water, quickly rinsing to not discolor the surface.

For removing coffee or juice stains from the floor, Wet a cloth with one part of glycerine to three parts of water, placing it over the stain for several hours. If the stain remains, obtain scouring powder and a damped hot water cloth.
Also,you can buy glycerine at drug stores.

For removing cigarette burns from heavy stains, try scouring powder and a fine grade of steel wool, or dip a scouring pad into water. For removing cigarette burns from hard surface floors, create a solution of lemon juice and water and dampen a cloth.

For removing candle wax from your harden floors, get ice cubes to make the wax brittle, and then use a plastic spatula to scrape the floor surface.
This may also be done to remove chewing gum from the floor as well.