carnaval carioca is a website dedicated to carnival in rio de janeiro, with lots of news published on this page.    

galeria do samba is a website focusing on samba and carnival, publishing news on samba schools and current events on this page.

carnavalesco is a website publishing news, pictures, and videos for the whole year on this page - só samba published news about carnival, and has sections dedicated to many samba schools in rio on this page.

while in rio during the carnival period, the magazine to look for is rio samba e carnaval, published in english and portuguese, it is distributed for free at the sambódromo, at the airport, in some hotels, and is some tour agencies.

to watch in real time some of the main carnival event, the website tvg rio shares lots of programming via this link.