How many Batman films are there now?
Batman
Batman Begins
Batman Forever
Batman & Robin
The Dark Knight
Have I missed any?
What order should i watch them in to get the jist of the story?
In modern(ish) times there's been the two Tim Burton ones:
Batman (1989)
Batman Returns (1992)
Which are pretty good, well from memory. It's been a long time.
Then following on there's...
Batman Forever (1995)
Batman & Robin (1997)
Which from memory are both pretty fucking terrible.
Then they axed it.
Now they've sort of "rebooted" with the two new Christopher Nolan efforts:
Batman Begins (2005)
The Dark Knight (2008)
Which are pretty ace (well supposed to be in The Dark Knights case anyway, as I haven't seen it).
Order watching; I wouldn't worry too much. It might be worth seeing Batman Begins before The Dark Knight, although I guess they're pretty stand alone. Wouldn't bother with the earlier ones at all, although the Burton efforts might be worth it if you're bored one evening, but they have no relation to the new films.