My own feeling about editing images is that it's as much an
art form as photography or painting - just different. Or maybe
not so much different as combining the two. The only problem
comes in when someone pretends an edited image is not
edited.

But this topic has been argued to death in this newsgroup.

Here's some practical advice:

1. If you haven't got $600 to burn on Photoshop, there are
cheaper ones that will do what you want. The one I use
is the GIMP - a totally free, open source image editor
that does a great job.

See http://www.gimp.org

2. Simple image editing is often very easy. Sometimes
there's just one button to push to "auto-enhance" the color
of an image, or very simple controls in "curves" or "levels"
to correct contrast, haze, and other problems.

3. Sophisticated image editing is very hard. There is a
huge amount to learn and a lot of it requires hours upon
hours of trial and error learning to see what the effects
of the controls are. Experts may think nothing of putting
many hours into a single image.

Alan