I very much enjoy the Dark eldar mystique and style of the models and the army, but when i look at all the different unit combinations and vast amounts of options i get confused.

Can anyone explain to me the Dark Eldar army style and how to use them in broad terms? (basically how to play with them) and maybe some of the main units that are universally loved and used by most DE players and maybe some units to stay away from? (just trying to get a grasp on the army)

Also what advice would you give someone wanting to start up a dark eldar army, who is somewhat new to 40k and has never used to Dark elves in WHF?