There are 5 books out right now, of a planned 7.
Game of Thrones
Clash of Kings
Storm of Swords (Part 1: Steel and Snow. Part 2: Blood and Gold) - Hardback is one book only, paperback split into two.
Feast of Crows
Dance of Dragons (Park 1: Dreams and Dust. Part 2: After the Feast) - Hardback is one book only, paperback split into two.
Bare in mind though, the paperback versions of book 3 and 5, are so long, they're split into two. So technically, there are 7 books to read out now if you buy the paperbacks.
Atm you have around 5200+ pages or so to read from start to 'finish'.
They're big. Long. And deep. And amazing
I've read them through 3 times now, and could easily start them again now. They're really good. Although book 4 (Feast for Crows) is imo the worst of the lot, and I really struggled to get through it the first time (and haven't read it again)