There have been a few people on this forum asking me about an updated version of my ITIL Foundation Essentials exam prep book now that ITIL 4 has been released. I'm happy to confirm it will be published on Monday June 3rd and you can read more about it here: 
https://www.itgovernancepublishing.co.uk/product/itil-foundation-essentials-itil-4-editionAs with the v3 edition of this book, it's just the facts you need to pass the exam, no more and no less. There's a longer book coming soon that covers the practices that aren't in the Foundation syllabus and gives a bit of practical advice so I'll update this thread when I know the publication date for that.