Vicodin is an opiate, so the withdrawals will be similar to that for any other opiate. They will include nausea, weakness, vomiting and shaking. Forturnately, vicodin is a very mild opiate, so these symptoms may not be too severe. The severity will depend upon how much you have been taking.
Some obvious symptoms would probably be stomach pains, body aches, fevers and chills, and the shakes. But you should be aware that your body is going to be detoxing in accordance to your use of the drug, so you could be facing minor symptoms to very severe symptoms depending on how much you took over the length of use.
It really depends on how much Vicodin you've been taking and for how long. Best case scenario would be drowsiness and agitation. Extreme case scenario would be sweats, agitation, shaking and nausea. It would be good to have someone with you while you go through this.
You should expect to notice your bowels moving a little more than usual with more watery-quality stools, feeling a bit more agitated than normal, perhaps sweating more than usual, and your pupils becoming less constricted (more wide-eyed).
It will take a total of one week before you feel totally normal, try not to become angry during that time, no matter how appropriate it may seem at the time. You may have stomach problems, if so eat bland food, but do not stop eating. Honestly it may be better to taper off.
You should expect to have cold/hot sweats, muscle aches, isomnia, diarrhea and a multitude of other things with your body to try to function without Vicodin.