In order to get the most out of the miniseries, it is best to read some of the excellent build-up to the it before diving straight in. The most essential prequel is the comic book collection titled The Omac Project, containing the Countdown to Infinite Crisis special. Not only is it a really fun read, the writers and artists really pulled out the stops to make it emotional, as we witness the death of one of the older Justice League members and a vicious battle between two of DC's Big Three. Also we are treated to some moments of Batman showing real emotion (something which DC realised had become too rare in the late 1990s and early 2000's) while trying to save the lives of those he has endangered. It's an excellent and dramatic story.
So The Omac Project is a must-read, and before that Identity Crisis is recommended. If you want to as well you could pick up Superman: Road to Ruin and Superman: Ruin's End – which tie in with The Omac Project and have one or two good moments.
But wait there's more – there were another three special short series that came after The Omac Project and led into Infinite Crisis and these were: Day of Vengeance, Villains United, and the Rann-Thanagar War. Although the last of these, a war set in space, has eye-popping art, the story is weak, it has no resolution and I'd recommend you give it a miss. The others are both entertaining reads, the best, Day of Vengeance (which deals with the problems with magic happening on Earth) being at times very thrilling and at times a little odd, with some deliberately “out-there” characters; Villains being a mediocre story about some anti-heroes against the world, with a lot of tension-building and a fun climax – this one has actually spawned a critically-acclaimed new team book that pops up every so often: the Sinister Six.
Finally I wanted to recommend Checkmate to the masses, a comic book which launched in the aftermath of Infinite Crisis and which sadly stopped running last year: It's basically a book about international politics and shady black ops manoeuvres with some super-heroics in there too. The discredited organisation Checkmate has supposedly reformed after the events of the Crisis, and has been supported by certain heroes, opposed by others. Previous members still feel it has a role in foreign policy, particularly in dealing with terrorism on an international scale. And they are then faced with impossible choices, considering their backgrounds, tense wars of words to pursue the best course of action, and operations where known spies are working alongside them.
Thus concludes my guide to this comic book event, hope you enjoyed it! Maybe some film updates will come before long....