DO NOT USE W3SCHOOLS EVER. EVER. EVER.
HTML & CSS: htmldog.com and the book, end of story. Widely-suggested books such as Zeldman's DWWS are usually bad—as in incorrectly bad and talk full of tripe.
PHP: the PHP manual and its comments (as well as ****loads of tutorials on the net) will suffice a lot of the time, otherwise O'Reilly books are usually good.