Resistors are usually the first parts that someone learns to read their value through its color code when playing with electronic circuits. There are usually many resistors in a circuit, and although learning to read them is not that hard, people still use "cheat sheets" or on-line calculators. First of all, i strongly encourage you to learn the color code, for it is simple and will save you much time. But if you still insist using "external help", at least do it with elegance! Here is a spin-wheel resistor value calculator made from Rob Ives. Download this pdf file and print it. Follow the instructions found here.