The Shadows, Volume 1, The Books of Elsewhere (Dial Books for Young Readers, 2010) by Jacqueline West is one on those hard-to-put-down books. I felt sympathy right away for Olive in this wonderful story. Here's a brief summary, without of course revealing the end:
11 year old Olive and her parents visit the creepy old McMartin house. Her mathematic parents are thrilled when they see the library and buy the house right then and there. Olive, who doesn't take after her parents in math--she's a creative person--senses that there's something strange going on in this house. After they move in, she discovers a pair of old spectacles that allow her to go into the paintings in the house. Olive also meets a talking cat who warns her about dangers. And, yes, she's going to be in danger!
I'm looking forward to more by this author! Volume Two: Spellbound will be released on July 12, 2011. You can watch a talk about the books on Jacqueline's site.