This is also an expansion pack for dwarves. It goes into extensive and loving detail into the history, characteristics and abilities of the '7 Houses' of dwarves. The neat part about the information they give is that you can choose to set your 'Chronicle' (as they put it) in almost any time-period of Middle Earth. In fact, they suggest that you make a multi-generational saga, where the sons and daughters (or other family members) carry on the quests and adventures. It's a neat way of making a character death more palatable (including carrying forward experience and knowledge, so the next one won't be *as* likely to croak and all your hard work won't be in vain:).
On a side note, I wish there could have been a *little* more detail about the Mines themselves, but I'm sure I can use my imagination and fill in the details. Also, I can get more ideas from other RPG sets that I own... it's not like 'dungeons' are underrepresented in roleplay games in general...