If you are more of a visual person and would like to organize your folders and files using different colors, than check it out how to use color labels in Mac OS X.
You can visually insert a radio button into your form and set its properties. Use radio buttons when you want users to select only one choice from a set of options.
You just bought Nexus 4 and you don't know anything about Android operating system, so I will guide you through literally first steps on this great phone.