If you shave your head it may help if the dandruff is just from not rinsing the shampoo from your hair properly. If it really is dandruff which is caused by a fungus, you will still need to use a medicated shampoo. Try out Nizoral, it's pretty good stuff.
All my shaven and forcibly bald friends note that you may get dry skin (kinda dandruffy) if you do not properly moisturize your head and shield the dome from the Sun.
They all use skin cream and lotsa sunblock.