Sorry to budge in. As I saw your post in AKB0048 and that you seem to start to check the group up, I just can't resist to give my 2cents and I don't want to drag the thread off-topic.
Do you know either Japanese or Chinese?
Their variety shows are pretty great, and Kin-SMA had a documentary special in January that was pretty moving. While it was not quite as extensive as the DVD documentary or the book it was sweet and to the point (though with some dramatization.) Here's a link that you can check it out if interested:
Being a fan for a while but even now when looking back to their history, it amazes me how the original members able to stick around for 4 tough years especially the one the are left are were all 13-16 back then.
A lot of their songs can only be fully appreciated if you learned about what happens in the group at time.
It amazed me more on how they act after the Japan earthquake last year. Out-donates and act more many corporations and entertainers and the effortes are still continuing.