This free Ebook from Microsoft Press does what the title says. In addition, if you aren't an IT pro, but fall toward the power user end of the scale, and you've read at least one thick book on some previous version of Windows, you can benefit from the book's general coverage of the Windows 10 user experience. Author Ed Bott is a seasoned writer and it shows, in easy-to-read prose that is eerily free of typos. Reading this book should reduce the scope for confusion or frustration when you get your hands on the release version of Windows 10. Importantly, you'll understand the reasoning behind the features that isn't always apparent the first time you encounter them.
Once the Windows 10 release date arrives, we'll soon see the usual raft of thick books that accompany every Windows release. Some of them will be more suitable for readers who are new to Windows, or who are new to digging deep. But unlike this book, the thick books aren't likely to be free. You can't really go wrong by reading an Ed Bott book about Windows that costs you nothing.