Go 90sShooter! I've been waiting for this thread to appear. I'd ask you how you like it but you're already using multiple big grin icons.
That last pic looks a little dark to me.
You remind me of myself a month ago (had just received the new hardware and was very excited). Post processing (beyond cropping) was / is a new frontier. Now if I weren't able to post process a pic, I'd be concerned and possibly even grumpy.
Enjoy. Learn. Post. I'd like to see lots of cool macro shots in your currently empty gallery.
Some suggestions - switch that 50D to RAW and leave it there. jpg's are good for final delivery but not for intermediate / in process works. When shooting macro on your reef, put the setup on a tripod. Pick a software package (I'm using PS Elements) and get comfy with it, or at least until you understand why you want to use something else.
You might want to consider calibrating your monitor if you haven't done so already.
We have the same camera and lens now, so if you stumble across anything neato, please let me know! I just tried remote shooting yesterday and I'll be doing that some more. You might want to try it once you're comfortable with your new abilities and talents.