Ant is correct - DO NOT OPEN THE CAMERA BODY. Don't take the lens off - to let the inside dry out. Modern cameras are pretty well sealed - but don't blow on it either, that iis just trying to force water past the seals. Water under pressure will get in where water sat on the surface won't.
Just don't worry about it - fresh water like rain isn't going to hurt. Wipe it off gently with kitchen towelling, or kimwipe. Then just leave it to air dry, not in the airing cupboard, you will cause condensation on the chip due to the difference in temperature.
Just leave it to to dry with the lens in place overnight. It will be fine. Saltwater is different matter. That will cause you problems because it conducts electricity quite well - and so your circuits will short. Rain water won't do this.
For the future - make yourself a raincape out of a large, strong, clear polybag. Just cut one corner off, just large enough for the lens to get through. Split down the side seams a bit from the open end (with camera and lens inside) to create a flap that you can get your hands to the shutter and lens, and your eye to the finder. A rubber band round the lens hood holds the whole thing in place - takes the worst of heavy rain off the kit. A clear bag like the ones pro labs send your prints out in.........rain cape for free! I keep two in my rucksack all the time.