One way to decode resistor values is by using a traditional quick-reference chart.
Type in "resistor color code" into Google or another search engine and you can find printable charts like this one. The formats vary, so pick one that you like. Download the chart, print it out and keep it at your workbench.
You can even print the chart on card stock and laminate it, and this will make it last a long time.
The advantage of this low-tech approach is that you don't have to have your computer or other device nearby when you need to look up a particular resistor.
Here is a screen shot of a resistor color code app on my iPod Touch 8GB 4G. You move the sliders to match your resistor and the app tells you the resistor's value. In the paid version of the app more bands are supported and the conversion works the other way as well.
We'll assume you're ok with this, but you can opt-out if you wish.