Undue artifacts and noise

[Chipper]

Amateur.
Unsuccessful in getting submitted images accepted by stock photog web sites.

I use Corel's Paint Shop Pro XI.
Finally overcame rejects due to focusing issues and CYMAK/RGB file problems, now...

Rejections due to "undue aftifacts" and "noise".

How do I recognize these and remove them before another rejection.
Do I need to take a class at one of the universities nearby?

Thanks!

[Jonathan Wienke]

Without seeing an image it's hard to make specific recommendations. It might be due to using a cheap camera or some processing problem, or simply not exposing properly. Post an image.