Cornelia Funke is the author of Inkheart, Inkspell, and the newest Inkdeath. I have a friend (BJ) who loves this series and has already seen the movie. The story is based on a man and his daughter who can read characters in and out of books. If you didn't know already, there is a movie starring Brendan Fraser. BJ has already seen the movie and is deeply into Inkdeath.
So, my opinion? While I found the first book (the only one I've read) to be imaginative and interesting, it was too slow for me. There wasn't enough action to keep me going and a lot of characters to keep track of. Although I checked Inkspell out from the library, I just couldn't get into it.
Maybe the film would hold my attention better, you say? Well, I haven't seen a good review of that either. I have this thing about books fitting well with movies. I nitpick about the details. From the trailer the characters enter the book world, but in the first book they don't. I have trouble with that. Maybe the trailers are wrong, though.
Anyway, if you like a deep book, and as BJ says, a young adult book, you might like to read the Inks. I think I'll pass.