Introduction
The Akatsuki kanji translates to daybreak. By most standards, it's a small organization. They have 7-10 members at the most and they are all S-class criminals who have left their village after causing death and destruction (also known as missing-nins). The requirements to join akatsuki are unknown; however strong abilities and slaying seem to be prerequisites. In contrast, Deidaras case tells us that some members are forcibly recruited.
Akatsuki members are usually seen in teams of two. The teams are each built to compliment each others abilities. However, in some cases, team members display animosity towards one another, but do not let it interfere with the task at hand.
We rarely see the Akatsuki meeting in person, instead, we see them using telepathy or some form of astral projection when needed. We were introduced to the group as a whole near the end of the first part of the series in the form of astral projection. One member even stated that it had been 7 years since they had regrouped in such a fashion. The Akatsuki only group together because they have have a common goal with each other.