Beginners Image Correction?

Hi,
we've a group of photographers (from beginner to advanced) at our company and we meet regularly to discuss images, techniques etc.
Now we want to start taking own images, correcting them and demonstrating what we actually do to make the image (hopefully) look better...
We are thinking of having a SHORT introduction/tutorial on the most important parameters.
Is there any intro available explaining these correction parms in brief? Thanks.

to me the tutorials are very clear and helpfull though sometimes a bit technical :)
there are also a lot of beginner topics with discusion about things like shutterspeed, apperture and ISO.
Besides that I found eNo's article usefull.
I hope this helps