Boy, to start with, detach that lens and remove the camera battery and, if your camera has a detachable Date/Time battery, pull it out as well!
Then, there are these little packages of absorbent "stuff" you can pack them with which can help, I''ve heard of people having good results with them, but I don't remember what they are called. I do know that you want unused ones. So, if you don't want to send your equipment in for servicing, that is the approach people seem to prefer.
I'll tell you what I did with a lens that fell into river water (no camera attached): I saw water droplets in there. I turned on my oven to a very low heat and left the camera in it with the oven door open for a day, checked out the lens, and put it back in for another day or two.
After a while of that I saw no more moisture. This was a "consumer" 70-300 IS lens, and it wouldn't have surprised me if it was "belly up", but I put it on my 30D and it worked! And, it kept working all the time I had the lens! It's been a few years, and I don't know where the lens is any longer, but still...
A camera body would be another question to me, stuffed with electronics and whatnot...like I said, pull that battery/batteries...what you do from there is, well, up to you I guess, although a trip to Canon would be the safest thing.