94% of forums are based around PHP, 4% HTML tabless designs and 2% CSS.
www.php.net has the best manual to learning PHP and it actually isn't hard at all. If you already know languages such as as C# and Java, you already know PHP with very slight changes. In PHP you don't have to define function, class, traits and variable types and instead of using using this. (note the period) youuse $this->. You don't have to use Namespaces either.