My 1st trip to Brazil for Carnival 2011 - Where should I stay in Rio? Ipanema or Copacabana or somewhere else?

I am looking to book a trip online to Brazil for carnival 2011. I have never been to Brazil before and I want to know what areas are good to stay. I am looking to go out to Carnival activities, parties and enjoy the carnival activities. Where are the main areas that the parade occurs in Rio?