Relics and Rituals II is a sloppy piece of work, over-all, though it has some good stuff in it.
Those getting into the setting should, almost obviously, pick up the Ghelspad Campaign Setting, but I'd prioritize Divine and the Defeated right beside it, and well above Relics and Rituals II. Divine and the Defeated and the Ghelspad Campaign Setting form the very heart of the setting, in my opinion, and do the best job of fleshing it out.
I will have to see if Waldenbooks has the new guides or Creature Collection out at some point in the near future, though...I've gift certificates currently itching to be used on Scarred Lands material...