It was originally planned to have one Hobbit movie, and then a 'bridging' film to link the Hobbit with LoTR, but I guess they've changed it now. It seems they didnt want to cram everything into one film, and having two will also allow them to expand on elements that were only alluded to in the book.
But this bridging film could still happen afterwards, which will mean another 3 films.
There's plenty of articles and stuff here
http://the-hobbit-movie.comTo tide you over until the first film is released, check out this 40 minute fan-made film, The Hunt For Gollum :
http://thehuntforgollum.s3.amazonaws.com/index.htmlIt was adapted from parts of the LoTR appendices, and it follows Aragorn as he sets out in search of Gollum to find out the truth about the Ring and to keep its secret.
Some of the acting and fight-scenes are a little hokey, but considering its $3000 budget, its not bad.