I'm just about to get into the Iron Man comics. From my research thus far, I gather that as a new reader, I would be best served starting with Extremis, then skipping all the Civil War/Initiative/World War Hulk tie-in stuff, and going straight to Matt Fraction's new volume of Invincible Iron Man that started with #1 this July, and just pick up from there. They're only on #8 now, so I wouldn't have to play catch-up too much.