Use a polarizer to eliminate the reflections on non-metallic surfaces (water, glass, etc..). A polarizer will also increase contrast and the intensify colors.
Tiffen makes several grades of filters. The cheap ones are not multi-coated that can increase the probabiliy of flare and ghosting and often add a color cast to the image. Some models may also cause vignetting when used at wider angles which you might want to test on your lens. Polarizers will also reduce the amount of light passing through the lens by about 1 1/3rd to 2+ stops. This will allow you to use a slower shutter speed than would be possible without the filter. You can find much more information in the Filters forum. Good Luck and Enjoy your Nikons!