nikon 18-55 cleaning

[stevo1210]

While changing my SLR lenses, I left my 18-55mm out for a bit too long uncapped next to an open window... so now the little lens on the inside (side that mates to camera) has bits of dust on it and also some unknown marks of some sort. How should I go about cleaning this?

I know I can use a blower to blow the dust off but what about those marks? Can I use a lens cleaning cloth or something alike?

My friend has a similar one and cleaned the inside little lens with a cloth and it left smears/clouding of some sort which scares me. He said it looks like there's a layer of oil over the top of that lens on his one though it doesn't affect photo quality.

[TCav]

In general, dust and small marks on a lens won't affect image quality, unless there are a lot of them.

A blower brush is a good idea for a first attempt, but if that doesn't do it, a microfiber lens cleaning cloth or LensPen is a good next step.