Losing weight?

Ok ~ I weigh more now that I did when I went into labor with my little girl. I am 7lbs. fatter than I was at 9 mo. pregnant. I need a great work out regimen that will help me to shake off the weight and quickly. I also want to get muscle. I am 33 years old and I know my metabolism is slowing down and I am not in as great of shape that I should be. I am willing to join a gym. I just want a little guidance - maybe a diet to follow maybe and some work out tips, vitamins and anything else that will help. I am 5"2 and I weigh 204lb. HELP!!!!!!