When it comes to landscape photography, deep depth of field and high levels of sharpness are often the name of the game. This excellent video tutorial discusses how to choose the right f-stop settings for maximizing the sharpness in your photographs.
Coming to you from Dave Morrow, this great video tutorial discusses choosing the sharpest f-stop setting for landscape images. Most lenses tend to reach their maximum sharpness somewhere around three or four stops beyond their widest aperture, normally somewhere around f/8 or so; thus, it is generally good to stop down a bit, especially since you will normally want more depth of field anyway. It is important not to stop down too far, though (generally past f/11 or f/16), as you will start to run into issues with diffraction and will start losing sharpness. Rather, if you need more depth of field, consider using the hyperfocal distance of your lens or creating a focus stack if you really need need maximum sharpness across the entire image. Check out the video above for the full rundown from Morrow and his site for an in-depth article on the topic from him.
And if you would like to learn more about landscape photography, be sure to check out "Photographing The World 1: Landscape Photography and Post-Processing with Elia Locardi."