Here are a few different image editors some free some not free there are many others

Image Editors
Photoshop by Adobe
The most expensive and an industry standard the top editing program with loads of features.
link Click here
There is a time limited trial try before you buy

Adobe Elements
A cut down version of Photoshop usually enough for most photographers
link Click here
There is a time limited trial try before you buy

The Gimp
Runs on windows macs linux and more and is completely FREE a very capable editor with similar features to Photoshop
Link Click here To handle Raw images use UFRaw Click Here

Picasa
A FREE editor and image management system from Google
link Click here
I use this one to manage my images

Paintshop photo pro
From corel low cost but well capable and many use it
link Click here
you can download a try before you buy demo

Have you checked the discs that came with your camera there are usually some Cd’s with useful programs including a free editor normally and other software to help with the camera and PC