My son just read Star Wars Visual Guide. He bought it at the book fair at his elementary school. This book had a section of villians. My son, daughter and I think that Count Dooku is the coolest villian, seconded by the short lived Darth Maul. The Count Dooku character has an intriguing light saber in the book. The statue in the Jedi temple of Dooku was in the book. I don't remember that from the movie. We had to go back and watch the movie again to see if we could see Dooku's statue. The first movie used the palace of Caserta in Italy. I actually had to go and show the kids pictures of the real building, then we could go in and see what was fake from the movie.
I remember reading the books of the Lord of the Rings Trilogy when I was a teenager, and thinking about the Saruman character, more than the other characters. I think it is because there really isn't all that much information about the villian, so a person can use their imagination more to fill in the blanks. The kids also thought Saruman was more interesting than Gandalf. They only saw the movie and the boy has the Visual guide from the Movie. The book is a little too advanced for the younger one. I might try reading it to them, and see what they think about the movie after reading the book.