Photographers call the hour after sunset and the hour before sunset "the golden hour." Seems like it should be "the golden hours" doesn't it? Well, let me save you the embarrassment of calling it the wrong thing - it's "the golden hour." Anyway, together, these two hours are called the golden hour because of the warm orange glow pictures have when taken during these time periods. It's not the only time you can take pictures outside, but many people (especially landscape photographers) would argue that it is the best.
Not only do the colors look great, but having the sun low in the sky provides good options for lighting. If the sun is to the left or right of your subject you can get some pleasing shadows that give your image depth and dimension. If the sun is behind your subject, you can get some neat back-lit effects - glowing hair included. Having the sun shining directly on the front of your subject is rarely desirable. Consider the following examples:
