Who do you talk to, the nurse when the doctor doesn't tell you about informed consent.?

Another doctor. If your doctor hasn't made arrangements to properly inform you about the risks, benefits and alternatives to surgery as well as other important things like what the scars will be like, how to care for incisions or physical restrictions post-op, then it is probably time to see another doctor unless you are on death's door. It's the doctor's responsibility, not the nurse's!