AdManager is for * Inventory management * Yield optimization * Ad targeting * Trafficking, ad delivery, and order booking * Creatives and rich media management * Reporting * User interface navigation * Account administration I don't think there is any relation to adsense but you need an adsense account to use it.
but they give a code to place on website...and i have done tht but could not understand how they are paying!
For real, I tried a little bit without good results and abandoned testing the Ad Manager. Maybe in the future I'll be back again.