How to clean lens?

I just have to stick my fingers everywhere, so now lenses on my digital camera are dirty. how do I clean them?

Camera lenses are not just bare glass, they are covered with a multitude of layers for optical purposes. Most of them are to reduce negative effects of light passing through the lens and, depending on the manufacturer, they vary in number, color and substance. It is ALWAYS recommended to use a soft, clean tissue, NOT to use soap or alcohol (they interfere with the chemicals in the coatings), ONLY the cleaning substance recommended by the manufacturer. I would add that this is wise, too. There is a multitude of lens cleaning liquids on the market, all you have to do is check which one is recommended in the camera's book, or on the producer's web page.

Go to your local Wal-Mart, Meijer whatever and get a cleaning kit. It will be a solution and little thin papers. Windex and a paper towel will leave a residue that will affect your photo's.

Lens Tissues,lens cleaner,Airbrush,etc.

I'm not a big fan of the lens cleaning tissues... after using them for 20+ years, I recently started using the microfiber cleaning cloths sold at photo stores for about $5. These things work far better than the tissues IMO.

Here's the basic lens cleaning procedure:
1) Blow off the front of the lens with compressed air - be careful not to shake the can or hold it upside down (otherwise the liquid will spray out and leave a residue)
2) Using the microfiber cloth, carefully wipe your lens, gently.
3) If the fingerprints don't come off, then you may need to use some cleaning fluid. I would go with the suggestions of other responders to use lens cleaning fluid you can get at a photo store, not Windex or anything like that. Or, just use a couple of drops of distilled water.

Remember not to put the fluid or the water on your lens, but put it on the cloth (if the fluid gets inside your lens, you are screwed). All it takes is a couple of drops. Again, wipe carefully to pick up the fingerprints. Then go back over it again gently with a dry part of the cloth.