drink lots of water do a bit of stretching.. but generally, take it easy/rest, Warm bath with epsom salts; possibly some Advil if you are really uncomfortable and a little bit of the "hair of the dog" that bit you. Try a gentle walk, which although it will hurt like the devil at first, should begin to loosen the muscles and ease the soreness as you go. Stretching if you can, and I also find massage helps -- some people find it doesn't, so this is going to be a depends suggestion.
You may want to try to soak in a warm bath, do some light stretching and use something like a foam roller if you have one to roll the tension out. I don't know what you do during the day, but I know standing for long periods of time, especially in one place can cause the calves to cramp.
A good massage may also be beneficial. You may have to give it a little time before the problem goes away, but I believe doing those things should help.