African nations - 52 nations competing for 5 spots.
European nations - 53 nations, 13 spots.
Asian nations - 43 nations, 4 spots, 1 in play-off.
North/Central Americans - 35 nations, 3 spots, 1 in play-off.
South American nations - 9 nations, 4 spots, 1 in play-off.
Oceanic Nations - 11 nations, 1 in play-off.
Hosts - Brazil.
I don't know what the equation is that FIFA use to work it out (probably £££££££ + $$$$$$$$ judging by the news) but got this from wikipedia. And there's loads of weird anomalies (Israel being in UEFA for security reasons, I guess, and Australia being in the Asian group for whatever reason.)