 
 I got a lot of gift cards for Christmas this year, a thoughtful gift which meant I could purchase exactly what I want and then pretend  that the person handed it to me wrapped in paper. One item I bought was The Book of Sith (the hardback book by itself, without the Vault) by Daniel Wallace.
The Jedi Path  is one of my favorite Star Wars books, since it looks like an in-universe artifact and contains comments made by characters from lots of different eras, and the Book of Sith  is very similar, except with more Knotters of Entrails.  These books work whether the reader is into the wider EU or not: they  can serve as introductions to characters such as Quinlan Vos, and will  read as mysterious and unearthly if the reader doesn't know the EU. If  the reader does  know the EU, she can have fun pinpointing all the connections between the various books.
 The  illustrations and different fonts really make the book look like it was  unearthed in an archeological dig somewhere. Different sections even  have differently sized pages. (The "Star Wars" logo emblazoned on the  cover and spine break the illusion a little, but I suppose they have to  be there.)
 One of the most interesting things about the Book of Sith is the way it  talks about the Nightsisters of Dathomir and connects Mortis to their  mythology. Seeing the Son and the Daughter of Mortis portrayed as  Nightsister gods made them feel more organic to the Star Warsuniverse.  I wish that idea could have been in the show, though, because not  everyone reads the tie-in material, and it's a major piece of the Mortis  puzzle to leave out.
Book of the Sith  did a lot of heavy lifting in  terms of continuity, using characters' asides to clarify what they did  or did not know or how one thing linked to another. Even the cultists of  Byss get a mention, and Luke's asides explained how ancient Sith  "spells" are really more familiar Force techniques. The notes from side  characters were informative and, sometimes, funny - especially the ones  from Quinlan. 
 I didn't expect much diversity, but The Book of Sith  featured major female characters like Mother Talzin, Asajj Ventress, and a diverse cast of ancient Republic Sith. Another thing I liked about it was the way it lent itself to different reading styles. Like The Jedi Path, it can be entertaining whether you read it cover-to-cover or just pick it up for a few minutes. The book  works as both a cohesive story and a fun collection of bits and pieces.