Orion have a YA Facebook page called Fierce Fiction. You can check it out by clicking the link. It gives information about Gollancz's YA list, competitions, review links, trailers, and more!
They are currently running a competition to win 5 of their titles (all of which look rather awesome!)
You can also find them on Twitter here
Readers of adult dark romance should also check out their other Facebook page - Gollancz Dark Fantasy.