It depends on what musclegroup you have trained.
Different muscles have different compositions of fast to slow twitch fibers and, as a rule, larger muscle groups (i.e. legs, back, chest) will take longer to recover and will stay more sore for longer periods of time.
Quads/hams are the worst for most people as far as recovery goes. It's not uncommon for mine to stay sore for several days after a good leg session, usually peaking in soreness the second day after.
On the other hand, smaller muscle groups tend to recover much quicker and stay sore for shorter periods (i.e. calves, abs, arms).
However, if you are sore, do not train that bodypart! It will be counterproductive! You grow outside the gym, don't train legs any more than once per week...they will need the recovery.