Most of the time, landscape photographers want everything in the image as sharp as possible, from the closest foreground element all the way to the farthest mountain or cloud. Accomplishing that takes more than simply setting your lens aperture to f/32 and shooting away. Focus stacking is one of the most common techniques for achieving this, and this great video tutorial will show you how it is done.
Coming to you from Dave Morrow, this helpful video tutorial will show you how to employ focus stacking to get maximum sharpness in your landscape images. The problem with using a very narrow aperture is that above f/16 or so, you will start to run into diffraction, which will visibly soften your images. So, instead of continually stopping down to increase depth of field, focus stacking relies on using a more mid-range aperture and taking multiple shots at varying focus distances, then combining them in post. Luckily, it really isn't a very difficult or time-intensive technique, and it's the preferred method of many professionals. Check out the video above for the full rundown from Morrow.
And if you really want to dive into landscape photography, check out "Photographing The World 1: Landscape Photography and Post-Processing with Elia Locardi."