Those people who like to woks on open source content management web based software they have weakness on open source free software like PHP, MySQL, Apache etc. here I am explaining about PHP tutorials on website. Lynda.com, Total tutorials is most popular websites where you will get more information about it from basic, advance and expert tutorials. But it is not free of cost. All of them you have to buy. I personally have weakness on Lynda.com and Total tutorials. But here I am giving some information about free websites on PHP.
On W3schools website, you will get basic to advance level text based tutorials on PHP and even you can take part free exam too. There is another option to become W3school certified PHP expert by taking examination but you have to pay for it.
PHP.net is the official website of PHP. If anyone wants to be expert on php, it will be the best option to choose.
Tizag: Tizag is similar text base tutorial website like w3schools.
Opensourcetutorials.com is a text and visual instruction based php learning website
Phpvideotutorials.com is video php learning site
Killerphp.com is Object Oriented PHP learning for Beginners. This is comparatively well but you have buy in advance stage.