I use a large white board which I put on top of my bed for photos. Natural light is optimal, but I find that daylight bulbs (which produce a whiter, bluer light) also help if you don't get much light in your home.
I ALWAYS edit photos. I'm not the best photographer and it's difficult for me to get crisp bright photos on the first try. I typically use Picasa, and sometimes Picnik for editing.
It has gotten to the point where I see a friend's photo on Facebook, or I see a gray photo here on Etsy, I just can't help myself but to go and edit it just to see if I can make it better.