Does the dust on digital camera lens affect the picture quality?

do we need to clean it as well? how often, and how? please give tips.

Yes if the lens is dirty/dusty If it looks dirty just wipe it with a clean cloth

It depends how much dust, if there is just a bit, then no, if the thing is full of it, then yes.

Yes it does. Go to your local camera store and by a small lens cleaning cloth. Most of the time their made of a lighter gauge but same material as a shammy. Because you don't want to use a regular cloth and scratch the lens surface.
Should be under $15.00.

Yes, dust on your lens can surely affect the picture quality.

More importantly, depending upon the constitution of the dust there may be more harm done to your camera.

You should get it cleaned professionally to lengthen it's life.

i certainly 'll affect the picture quality..

you need to clean it gently with a leans cleaning cloth which you can get a the camera shop. just clean it when you notice that it's dirty.

I wouldn't worry about a few specks, but clean the lens often with products made for the purpose. Get lens cleaning cloths and fluids at camera stores. Don't use paper towels or window cleaner. They will scratch the anti-glare coating on the lens and really mess stuff up. Kleenex is nice and soft, but has a lot of lint and sometimes chemicals that will damage the coating.

clean with a quality `cloth`.
on SLR lenses fit filter to end ring ,cheaper to replace filter than lens.

It depends how much there is. If there's quite a lot, then yes. Try using compressed air to blow the dust away, then use a lens cleaning pen to finish the job. Both can be bought from Jessops.

Dust on a camera will affect the picture quality. You need to clean it regulary( once a week) use cleaning wipes to do so.

yes

Yes it does