Learning any language is easy as long as you know the basics i.e variables creating functions & classes and statements, rest of it is just finding the right functions of the said language that you need.
http://www.php.net/manual/en/funcref.php For example if you want to do something with arrayslook up
http://www.php.net/manual/en/book.array.php the function names are self explanatory, so as long as you know the basics, it's easy.