Actually, another thing I wanted to mention about the Sith... There is a triad in power, three darths that all answer to an Emperor that only the triad knows of (by face and name), the rest of the sith know of him and refer to him as the emperor, our master, etc.
Also, under the council is an Executioner, basically a voice of the council and the Emperor (sorry, this role has been taken). The rest of the sith are masters that have their apprentices. Very similar to the Jedi, but in smaller scale.
Hopefully that clears everything else up about the Sith.
Any questions let me know ^^