You may have wondered "How do pros make those wonderful landscapes where everything seems to be in focus?" Well, it is not merely by closing down the aperture of superb wide angle lenses. In fact, shooting at smallest aperture only introduce defraction - sharpness killer.
Instead, they maximize DOF (depth of field), the region of acceptable sharpness, by focusing at the hyperfocal distance. The next time you shoot, pay attention to the following table above to improve your landscape shoot.
So what is hyperfocal distance? Whenever you focus your lens there will be an area that is in focus and areas that are out of focus. The area that is in focus is referred to as the "focal plane". Focus there.
Example of use (see diagram above):
If you were using a 24mm lens and select f/11 as your aperture, the Hyperfocal Distance would be 2.5 meters or 8.4 feet. If you focus at that hyperfocal distance, the depth of field in your image would be from half of that distance (1.25 meters or 4.2 feet) to infinity. Since modern lenses don't have DOF engraved marks in their barrels anymore, you need to estimate where in your scene is that hyperfocal distance read from the table to focus on. As long as it is approximate you'll be fine.