At the top are the "Governing Body" which are a group of a dozen men or less who are responsible for crafting the theology of the religion. They also write, dictate, or otherwise influence much of what appears in the WT literature and talk outlines.
Next are Branch Overseers that are responsible for running a Branch and managing the Organisation in their country or countries.
Below them are the Circuit Overseers who manage two or three dozen congregations by actually traveling to visit each one several times a year.
In each congregation there is a senior elder whom all the other elders in the congregation report to.
Then there are the elders who manage the congregation and do most of the talks.
Under them are the Ministerial Servants who do a lot of the busy work and fill in for Elders when one isn't available.
Next are the baptized males. Generally the one's pioneering are considered in the higher standing.
Under them are the baptized females.
Lowest on the totem poll are the Publishers.
I hope this is somewhat helpful to you. But it is by no means an exhaustive explanation of the intricacies of the JWs Organisation.