Lost in a good book by Jasper Fforde (Penguin Books, 2004).
This the second in a series of novels set in an alternate universe reminiscent of modern England as viewed by someone on mind-altering drugs. I read the first novel (The Eyre Affair) several years ago and it basically went way over my head. Life in the UK is an alternate universe to me already, even without people who can jump into books, and I am not a fan of literature by Austen, Dickens, etc. If you love traditional English literature, understand life in modern England, and have a overly developed sense of humor (for example, you love Douglas Adams), you will probably enjoy this book. There are over 131 reviews on Amazon, if you’re looking for a more favorable opinion than mine.