DSLR cameras are super fun to work with. I use an Olympus E-520 with a 35mm macro lens most of the time. I don't really have my own lighting arrangement, so with smaller guys like corn snakes I tend to set them up on my windowsill on slightly overcast days. Personally, I don't like the effect that too much sun can have - harsh shadows in awkward areas. It also tends to wash things out. Here's one of my most recent shots of my lavender, Pandora:
She was curled up in her water dish, and I managed not to disturb her on the trip to the window.
Soo yeah, my suggestion is to go with slightly overcast days if you're using natural light, as it won't wash out the subject as much but still provides adequate exposure. Experiment with angles to get more interesting shots. Aaand yeah, have fun!