Try writing a blog... It's harder than it looks, but is straightforward enough to understand how to get started, at least.
So far, the best resources that I've found for each language, PHP and MySQL's version of SQL, are the sites they come from themselves...
PHP: Hypertext Preprocessor and
MySQL AB :: Developer Zone respectively.
W3Schools Online Web Tutorials also has tutorials for learning PHP and SQL, but I can't vouch for their quality... They do, however, have excellent (X)HTML and CSS tutorials, so I can't see why their other tutorials wouldn't be at the same level.
As for how long it takes... That's entirely up to you. Anywhere from a month to a lifetime.
__________________
People often say that 'beauty is in the eye of the beholder,' and I say that the most liberating thing about beauty is realizing that you are the beholder. This empowers us to find beauty in places where others have not dared to look, including inside ourselves.
--Salma Hayek
My blog:
Adam's Peace