Earthbound Light
Fingerprints???? Break her fingers! Fingers do NOT belong on lenses!
Seriously, I have a lot of use for Bob Johnson:
http://www.earthboundlight.com/phototips/lens-cleaning.html
Lots and lots of voodoo on this.
-- Soft, non-gritty material (clean, washed cotton, microfibre, PEC-Pad)
-- Distilled water, methenol, condensation, Eclipse
-- Blower or blower brush
Prevention is best cure; use your lens hood and lens cap.
If you want to provoke teotwawki, suggest using (or not using) a filter to protect the front element of your lens. (Just search any camera forum.

)If you do choose to use a filter, note that digital cameras do not need UV protection and a skylight filter is pink - easily done in post processing. Should you choose to use a protective filter for a digital camera (and I do in the bush), the best is probably the NC (neutral clear). Remember, NO filter will improve the quality of your image and a cheap (<$50 - $100) filter can be depended on to degrade the quality of a good lens. In any case, take the filter off when doing indoor flash portraits, etc.