Platitudes and Paper Towels

Some time when you're not camping out in hell, could you explain how the whole residency thing works for those of us who are clueless? I have a vague sense of how doctors get trained (you go to med school, and then have an internship year, and then do a residency in your chosen specialty, for two years to ten depending on whether your specialty is Family Practice or Neurosurgery) but the actual parameters of this form of indentured servitude are a mystery to me.