This book appears to throw you in at the deep end. If a new programmer just looked at Day 1 it could be quite intimidating, as it goes into classes, inheritance and has you type a lot of code you won't understand, but Day 2 moves into explanations of variables, data types, operators and so on, which will make that beginning programmer sigh with relief.

I think it would be helpful if you already understand the basic concepts of programming and want some practical experience with Java; I wouldn't recommend this for anyone who doesn't already have some experience (even if tiny) because the nuances of things like class/local/instance variables might be very confusing to someone who has only just learned what a variable is. In short, it's better for a novice than a complete beginner.

This book does guide you towards best practices, and helps with the more abstract areas, and seems good at bolstering existing knowledge.