The book I read to research this post was The Samsung S4 Manual The Complete Galaxy S4 Guide To Conquer Your Device by Daniel Forrester which is a very good book which I bought from kindle. This book is written in an easy to understand way and although it's only 68 pages certainly covers all the basics with this smartphone. The processor is a quad core 1.6 GHZ so is only a small upgrade on the S3 but the memory has gone from 1 GB to 2 GB and the software is much more efficient so the phone is much faster at doing things. It has a rear 13 MB camera and a front 1.9 MB camera and has technology incorporated to let you take several shots and combine them into 1 photo and also there is a built in eraser app that lets you remove moving objects from the background if they are a bit blurred for example. It runs the Android 4.2.2 operating system called Jelly Bean. I think as updates become available you can upgrade that as time goes on as with most smartphones. The case and the bezel to this phone are smaller but the screen is actually bigger which does mean things like the keyboard might take a bit of getting used to as they are bigger than the previous version. I did see a review of this phone in a technology magazine and it was rated as the best smartphone available. I enjoyed reading this book and I know it's quite a new phone but there doesn't appear to be that many books and ebooks available about it although I am sure that will gradually change.