Who are the atatuski?

Answer 1

in Naruto:

Akatsuki (暁; Literally meaning "Dawn" or "Daybreak") is a criminal organization of S-Class missing-nin and is the most wanted group in all of shinobi world. Their main goal is to collect all of the tailed beasts for their plan of world domination. As such, Akatsuki, despite initially having a minor role during Part I, have become the primary antagonists in Part II.

Akatsuki at any given time is composed of no more than ten primary members, all of whom were S-Class criminals of their own respective villages. Members always work in teams of two with the exception of Zetsu, who functions as the organization's spy, and make use of their unique skills to the team's advantage. Team members must function very well or at least to accomplish their task even though they have a mutual problems with each other. The organization is rarely fully assembled, as seen in the end of Part I, when one member said it was the first time in seven years when they were all together.

Akatsuki is widespread, spanning several countries with agents in various places. When one team finds a tailed beast and has to begin the job of sealing the beast, they have hidden hideouts with many traps ready, to do the three-day long jutsu.
source: http://naruto.wikia.com/wiki/Akatsuki