These filters are easy to use. Using a circular polarizing filter will allow you to adjust how it impacts your shots by simply rotating the front element of the filter. As you do this, you’ll notice that colors and reflections in your shot change. Once you’ve got it to a point that you like, simply take the shot.
For the greatest impact try to keep the sun at 90° to you (ie to your side – not at your back and not shooting into the sun). This will help your polarizer to have the greatest effect.
Be aware that shooting in low light, overcast days or at night with a polarizer is not advisable – it’s like wearing sunglasses indoors and will cut down the amount of light getting through to your image sensor.
Take a look here for more info, advice and examples:http://www.advancedphotography.net/circular-polarizer-filter-circular-polarizer-filter/http://www.digital-photography-school.com/how-to-use-and-buy-polarizing-filtershttp://leefilters.com/index.php/camera/polariserhttp://www.pixiq.com/article/polarizing-filterhttp://www.picturecorrect.com/tips/polarizer-filters-in-photography/http://www.luminous-landscape.com/tutorials/polarizers.shtml