Google AdManager

Hi all,

My application was approved for early-access Google's AdManager program or tool or whatever it is. I'm excited, but don't really know why as:

1. I have no idea what it is
2. I have no idea how to use it efficiently
3. Why is it good for me

I already managed to push some of my adsense ads to it and manage them from there, that was easy. But that was all? A new adsense management interface?
There is an inventory 'zone' which i should use somehow *sniff*. The self-help program talks me on a language I don't really understand, see it yourself: http://www.google.com/support/admanager/publisher/
My answer for most of the things covered there is "Huh?"

Something else: Upload creative media. Will this be another AdWords-like thing as well?
I understand that this 'release' is a result of Dubleclick's buy-off by Google so they might be somewhat identical? The problem is that I know about Dubleclick as much as I know about interstellar traveling.

Could somebody enlighten me on this subject? Please?! I hate when I don't understand something

Thanks in advance