Hi
Dennis H!
There's a great list of freeware apps right here on these forums. You can check out the photo editing programs
HERE. While I've never used it, I know that a lot of people like Gimp.
As for your photos being to dark and the color being off a bit, here's a few tips to keep in mind:
Always use your flash. Turn your flash on manually. You should see a "lightning bolt" symbol with an arrow on the end of it (at the bottom). This means that your flash will always fire when you take a picture. If it has a circle with a line through it, then it means it's off. If it has a small capital "A" next to it (lower right of symbol usually) then it means it's in automatic mode and the flash will fire if it thinks it needs too...don't trust it. It's a good idea to always use your flash. It'll brighten up both your subject and background, and also help to aleviate the natural shadows on peoples faces. A flash will also help the color.
Stand still and hold the camera still when taking photos. There's usually a 1 second delay with digital cameras, from the time that you that you push the button to the time that it actually takes the photos. A common mistake is that people push the button and then move the camera...causing a blurry photo. It's also good practice to hold the camera still for 1 second after you see the flash go off. Try standing with your left foot just in front of your right foot, spread out about shoulder width apart (it'll steady your entire body).
Don't block the flash. Lots of people hold the camera in such a way that either their left pinky or ring finger will block the flash, or part of the flash. Hold the camera with your pointer finger and thumb, curling up your other fingers like a fist, then rest your knuckles against the sides of the cameras to help brace it. Alternately, you can spread you fingers out and put them in different places around the camera taking care not to block the flash or lens itself. Pinky fingers on the bottom of the camera help a lot too.
Do these a few times and it'll become habit, helping you to get a great photo every time!
Hope these tips help!