I need to know what are the right order of the PHP learning steps, I have learnt PHP basics, OOP basics too, and I made some small projects using them, however, there are a lot of subjects and techniques in PHP and I'm confused with what to begin first and then what etc?
Following a methodical way when learning anything can save a lot of time.
Please don't only tell me the next step for me, I need to know the full Roadmap for studying PHP?
PHP can do many different things with many different libraries and supporting client-side scripting.
Things I used to learn PHP:
A blog with image uploader.
An AJAX based tic-tac-toe game.
An image storage site.
There are many things PHP can do and no specific Roadmap you should follow. If you feel there is something you would like to write, simply write it.
I believe you've done the methodical part. The next best step is experience in the real world.
PHP is not as complex a topic as something like Java, C++, or .NET.
If you really want to continue studying PHP, I would move on to design patterns (at least MVC/Model 2), associated technologies (SQL, JavaScript, HTTP), and then how PHP is deployed to enterprise (not that it's a particularly great choice for enterprise). With that knowledge you should be able to jump into a framework like CakePHP or CodeIgniter with a strong appreciation for what they're doing for you.
I think you should know some programming basics first: like variables, control statments.. PHP also involves client-side coding: HTML, CSS, Javascript, and you'd better try to write some static HTML pages first and make yourself clear about the relationships of them, and how they work together.
If you've done the above, I think you can do some real PHP programming: I suggest you start with writing a simple guest book (with MySQL, if you could).
When you have finished your first guest book, try to improve it: functionality, security...
It is also my start with PHP.
After all, PHP programming is basically dealing with web but also it could extend to vary fields: system, algorithms ... Try to learn whatever you need in your real practice, and I guess it won't take long to make yourself a real pro