What are the standard ways of finding out how much a home is worth?

My grandparents gave me a house three years ago before they died. The house is located in Utah. It is too far away from my work, here in New Jersey to be of any possibility of using my house. Therefore, I am planning on selling the house. It has four bedrooms and two bathrooms with a nice place for gardening. The thing is its very old and the designs were classics. I want to sell my home for a good price. What are the standard ways of finding out how much a home is worth? I also want to know, how I can make improvements to help me make a good selling price.