Having bought many expensive computing books over the years, I find that O'Reilly tends to deliver what I'm looking for pretty much every time. With Web Database Applications with MySQL and PHP there was no exception. I found I was able to get MySQL and PHP working on Linux pretty quickly, by using this in combination with the PHP, Apache and MySQL install notes. Following that I have been able to get started on developing real web applications within a couple of days, and the examples given in the book have been useful and clear.
Although there is a brief "What is a database?" and "What is a webserver?" discussion at the start of this book, you should not expect to learn web concepts, SQL or HTML here. Having done lots of Oracle/Ingres and Java development before I hit the ground running. However, it might be too much too soon if your background until now has been building static webpages with Microsoft Frontpage.
It is interesting that there is no discussion as to when PHP and MySQL might be an appropriate solution. Indeed the back cover of the book asks "What do eBay, Amazon.com and CNN.com have in common?", answering that "they are all applications that integrate large databases with web interfaces". Interesting choice of examples, as Oracle is almost always the database of choice for this kind of very large implementation (including those mentioned). It seems to me that the real advantage of going down the PHP / MySQL route is that the software is free and hosting is very cheap. A dedicated chapter outlining the strengths and weaknesses of the PHP / MySQL approach would have been a nice addition.
All in all, I'd recommend this book as an excellent technical starting point if you want to use PHP and MySQL for your next development project. Having this book to hand will mean you don't need to delve too heavily into the nuts and bolts of the documentation for the first few weeks!