if I was only going to have one book on web coding this would be it
The books in O'Reilly's Nutshell series are neither definitive detailed references nor tutorials. Instead they provide a handy, concise reference for something you've already learnt but can't keep entirely in your memory, and would otherwise need several books for. The Nutshells generally fill this role very well and are highly regarded; this is no exception.
I think on the whole I would give this a Highly Recommended rating.