Head on over to DSLR Tips Landscapes Workshop
. Check out the site for more workshops.
For a tutorial on Depth of Field try Understanding Depth of Field in Photography
over at CambridgeInColour. If you don't have, or find it difficult to use, a DoF preview button then you might also find it useful to print out a DoF table such as the ones from this calculator
for each lens and, of course, your camera type. Don't forget that there's a penalty to pay if you select too large an f-number. See Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks
for more on this subject.
Once you have your DoF sorted then you will need to check the shutter speed selected by the camera. Adjust the Ev compensation if needed and bump up the ISO if necessary to get a faster shutter speed to freeze movement.