Lots of good advice here already. Shooting outside on overcast days is the easiest way for most people to take well-lit photos. I own lots of hot lights, speed lights, remote trigger systems, soft boxes, reflectors, and other professional camera gear. I generally prefer to use nature's giant soft box, though. A bright but cloudy day gives you ideal conditions to casually capture almost hyper-detailed looking scenes by making it easy for your camera's sensor to capture, as the dynamic range is compressed so the exposure can be just right for the entire image without cheating one end, the other, or both. This is just setting a knife on some ice on a bright, but cloudy winter day and snapping the photo, for example:
That said, sunny days work great as well, if you shoot in the shade. A shady spot on a brightly lit day outside often yields a surprisingly bright, but diffuse overall lighting.
This was shot outside on a sunny day, but in the shade, for example (underexposed for style, you probably wouldn't have guessed it was sunny when this was shot):
After you get a feel for how lighting effects a photo, you can play around. A combination of a fast (large aperture) lens, a yellow wall and a shiny polished granite countertop yields this photo (the countertop is dark green with flecks of gold when viewed from a more direct angle):
It's also a good idea to play around--digital photography means you can just keep snapping after all. Even though you don't generally want to point your lens towards the sun, sometimes strong backlighting can be fun too. This is a quick snap with a mobile phone at a highway rest stop. If it was front lit or had diffused lighting, it would probably have been a much more boring photo of my 0450cfzdp sitting on a picnic table:
