There are many different image editing packages, generally I use Fireworks to edit and convert my photographs for use on the website.
I usually crop my images, enhance the lighting sometimes, and have used the “clone” tool to remove unwanted parts of the photograph (such as the table edge or scenery joins).
Cropping
One trick to use with a digital camera, is to take a long distance shot and then crop.
This is the original shot (which was 2400 x 1800 but has been resized to 600 x450 so to fit on this page).
The next stage is to decide on the area to crop, in this example I am aiming to get a picture of the Hydra.
You can now crop, so this image is in fact actual size.
Therefore you get a better result than if you tried to take the image of just the Hydra.
This process works even better these days with the higher Mega-Pixel (MP) cameras available now.
Sizing
As I have moved hosts recently (and connectivity is less of an issue for most people, I am now re-uploading a lot of my photographs from the 600px I used before to 1800px.