After only 2 days, I was coding PHP while glancing back at this quick-start guide for help. In a week, I was writing my own first simple application in PHP.
I've read plenty of PHP books by now, but this is book is the one I always return to for a reference.
Overall, this book is the fastest solid PHP foundation you'll find - assuming you're lazy like me and prefer to learn visually instead of plowing through endless code.