I totally agree with Jester. Even before you get your housing, take lots of pictures....shoot until your fingers bleed! The film is free! :tong: Seriously, the more you know about your camera out of the housing the easier it will be to use in the housing. Although all the features are accessable in the housing, it's not so handy to look at the camera to make sure you're in the right place.
After you get your housing, shoot with only the internal flash for a while. Learn what the camera itself can do. You'll be surprized at how strong the internal flash is. I used my C-4040 for over a year before I added an external strobe and got lots of great photos.
I would recommend you buy a larger CF or XD card. Personally, I like the CF card the best. I have a 256mg and plan to get another rather than a single 512mg card. Since I download often, and on a trip I can download twice a day and burn CD's on my laptop, I see no reason for the bigger cards. The XD card works well for me, they are just so small and hard to keep up with outside the camera.
Next I would invest in a good smart charger and NiMH rechargeable batteries. I've got a MAHA 204 charger that's the bees knees and 4 sets of 2200mg NiMH batteries. These batteries last me for 3 dives, 2 for sure with plenty of juice left.
For photo manipulation afterwards, I like Photoshop Elements 2.0. It's only $99 compared to $600+ for the PhotoshopCS and it does everything you need, just not all the bells and whistles.
Have we confused you yet? :biggrin2: