This is the official Marvel Cinematic Universe Timeline, as found in ‘The Art of The Avengers.’ Click on the thumbnail for a much bigger version.
This timeline puts into chronological order the events depicted or described in Iron Man 1 and 2, The Incredible Hulk (which apparently is official canon, despite the recasting), Thor, and Captain America, ending with the assembling of The Avengers a mere eight days after Tony Stark declared to the world, ‘I am Iron Man.’