LordBax

I had this problem as well but after a lot of searching around I've found the solution. In the new version of mystcraft they've changed the mechanics of descriptive books. You now need to make them using a book binder (the recipe is in NEI). The recipe for a descriptive book is one leather and at least one piece of paper made in the book binder (adding more does something that I'm not sure about yet). More information on book binders here http://binarymage.com/wiki/doku.php?id=writing:writing#getting_started