If you are not from Brasil and you want to celebrate carnaval in Rio, what should you do? Do you just buy a ticket to Rio, book any hotel and just enjoy? Or is that a recipe for failure? i can imagine that if you don't know the spots you might end up in a very unfavorable position where you are actually there but you get completely lost in the crowds. Are there tours and are they worth considering?
I have not been to Brazil myself yet, but this is on my list, so here is what my research thus far has found.
As hippietrail pointed out, the Carnaval in Rio (and in Sao Paulo) has grown to be a huge event that requires a purpose-built stadium in each city. These Carnavals are put on as big mega-parades by Samba Schools and are nowadays meant to be seen more than participated in. These cities may also have smaller neighborhood parades called blocos but those are not the main focus for these big-city Carnavals.
That being said, there are always ways to participate. There are huge numbers of balls and street parties to explore, and if you really want the full experience you can basically join one of the samba schools in the Rio Sambadrome by buying a Carnaval costume at the typical American price ($500-759), which entitles you to then spend about an hour parading right with a samba school inside the -drome in your costume. The benefit to them is that your costume purchase is enough in Brazilian currency to buy the costumes for the entire school, many of whom could not otherwise afford such extravagance. This strikes me as an ingenious way of creating a win-win situation for everyone.
If you're like me, though, and prefer the classic carnaval da rua - literally, "carnival in the streets" - then you will want to look to the other cities. With the Rio and Sau Paulo celebrations relegated to the -dromos, the city of Salvador in Bahia now has the largest carnaval da rua and the world record for largest street party on the planet. So we're still talking "huge" and "book well in advance".
If you're still like me, you're thinking, "I like that in-the-streets feel, but maybe with less people, yeah?"
Well, you have options. So far, I've been tipped by friends and Internet to the following suggestions, whose reputed merits I will summarize briefly:
Personally, I'm leaning toward Olinda or Recife...their celebrations sound exciting and fun in a very democratic, participatory way. And I like that they are said to have some of the qualities of the old masquerade European Carnivals.
Your mileage may vary, but what I have learned so far is that there is definitely a perfect Carnaval for every type of person, somewhere in Brazil. The trick is figuring out which one is for you.
"Do you just buy a ticket to Rio, book any hotel and just enjoy?"
That's about exactly what I did for my visit in February 2009. Well I chose my hotel carefully - a decent hotel - search engines are your friend as are reviews. I chose a major airline as well. I booked tickets to the Sambadrome online and for one of the Samba school balls at a ticket seller in advance. I went on my own.
The Sambadrome experience is great for the first time, the regular seats are concrete steps so if you can take a cushion to sit on that would provide better comfort. In 2009 it ran from 9pm to 6am in the morning the next day for 2 nights. Each night 6 schools were paraded. It is not necessary to stay all the way through to get a feel of the event, but you can.
Check O Dia - the local newspaper for the Blocos - the street parties all around the city. There's more to Rio than just the Sambadrome. Transport: I found Taxis to be safe though would cost more money than other means of course, also buses. The metro/subway/underground is safe too though I didn't use that.
Do some homework. Learn some basic Brazilian Portuguese - this will make all the difference for meeting local people. Take some classes and a little private tuition - that's what I did. I was far from perfect in my grasp of the language and wished I had learnt more but what I did know really helped.
Get your vaccinations in advance - ask which ones needed. In Rio I doubt you would be exposed to anything problematic but take the opportunity to get them done - as you may want to adjust your plans while out there to go to places where they would be needed. I think I had typhoid/diphtheria and definitely yellow fever - these are really only needed in the tropical regions though.
Apart from the Carnaval attractions, the obvious ones include Christ The Redeemer (Christo Redentor) statue and Sugarloaf mountain (Pao d'azucar) as well as Copacabana and Ipanema beaches - all which I visited. I'm sure that some research will reveal more attractions. I would be intrigued by the street art and murals on my next visit - a friend who went at a separate time has seen those. Most have probably heard of the Favelas - the slums - these are places to avoid due to the crime and violence - which leads me to say...
One more thing: don't tell too many people of your plans. When I started telling people (including those who hadn't been) I got scare stories. So I stopped telling people. I went - and came back just fine!
Update additions: Added date of visit. Added point that the Sambadrome performances took place for 2 nights. Add point that ball tickets can be bought online in advance. Added notes on transport. Added notes on other attractions.