Oblivion:Marker Books

If you open such a book, a sign will appear on your map, marking a place.

ID	Item Name	Marker	Where to find
000C55DF	Agnar's Journal	Fanacas Kingscrest Cavern Quickwater Cave	Dive Rock. Note: This does not work in the same way as the other marker books. Merely approaching the lookout point is enough to get the markers. You don't need to read the book or even look at it. (However, the script that adds the marker points IS on the book, though it's not obvious that this is the case.)
0002C8DD	Cleansing of the Fane	Malada	Mach-Na's bookstore in Cheydinhal, the First Edition bookshop in the Imperial City, or a purple book found in the bookshelf on the east wall of the 1st floor of the Mystic Archives and in the Chironasium upper level on the third shelf of the bookcase in the northeastern corner.
00022E65	Knightfall	Frostfire Glade	The First Edition in the Imperial City during the quest Tears of the Savior.
00026B1D	Modern Heretics	Azura's Shrine	Cloud Ruler Temple, or the Mystic Archives in the Arcane University.