Corean was smiling on me today!
Okay good questions all.
Let me explain something to you about this little land. Much like FR in it's days before it got to be what it is now, BIG, the Scarred Lands are STILL being developed. So as of yet, there's no MAIN book. Just a series of them. However that will change VERY soon as the Hardcover for Ghelspad, much like the one you now own, will give more graphical and detailed analysis of this wonderous land.
The Creature Collections ARE both generic AND SL specific. One of the beauties of trying to make a world that fits into ANY campaign. CC1, being the first books, has some flaws, but nothing that I feel COMPLETELY detracts from what the Scarred Lands has to offer. CC2 though is a vast improvement, and is also more SL specific. Now Relics and Rituals, this is where the Scarred Lands shines. They have not just new spells, but magical items, pr-classes, AND a whole new way to cast spells called RITUAL magic. Then there's the Wise and the Wicked, a who's who of Scarred Land faces, both fair and foul. The Divine and the Defeated, gives DETAILED understandings of the gods, the Titans and their servants, as well as some groups devoted to each, along with spells, new domains AND even some background on each of the gods, both the Eight victors AND their demi-god followers, such as Goran, and Manawe, Lady of the Seas. Hollowfaust...well Hollowfaust is a odd duck, and in the Scarred Lands, that's SAYING something.

It's the home of one of the more mysterious groups, a city of necromancers devoted to ideas such as research, defense and trade. These aren't your normal insane, power-mad necromancers by ANY stretch of the imagination. Mithril, is like Hollowfaust, a book about one of the more predominant city states, and home to the Mithril Golem, seat of Corean's power.
If you need any more info, don't HESISTATE to ask.