Personally, I did not learn PHP throught any tutorial or book.
I think this is the best way to go:
-First, if you are not motivated (have a goal in mind or really like this stuff), it wont be easy.
-Learn HTML (very easy)
-Get some basic programming knowledge (loops, variable, functions, etc...). You can look for JavaScript or C tutorials if you do not find anything decent about PHP. PHP's syntax is very similar to these languages.
-Download the PHP documentation in CHM format (precompiled HTML - only for Windows!) from the official website (www.php.net). It is the best documentation I have ever seen!
...and start experimenting