Hi, I searched link from where one may learn Wordpress not only starting level but from start to expert level means there must have tutorials for how to add custom code in wordpress & so on.. but I didn't find any web site... if any then kindly forward link ....
Thanks
Are you interested in any particular aspect of Wordpress (such as creating templates or plugins)? Or are you hoping to get a good overview of all the tools?
You can find an excellent collection of Wordpress tutorials here.
The WP Tutorials are great when you know what you are looking for.
If you just want to understand how WP works then set up a WAMP or LAMP environment on your local machine, download WP, install it, and then start looking at the code to see what is doing what. If you understand PHP and MySQL then this will be an easy way to learn.
I find it best to download some of the free templates and look at how they are created. This will give you allot insight into how to customize certain aspects of WP.
Once you formulate specific questions by looking at the code and playing with it you can use the tutorials to gain better understanding.
Hope this helps.
I know Aaron Jorbin is working on a Wordpress Plugin Developer handbook. http://wpdevel.wordpress.com/author/aaronjorbin/ . That might be a good resource to help you get started with Wordpress development in general.
If you're looking for a general resource for all things wordpress, including development, I would check the wordpress.org Codex: http://codex.wordpress.org/Main_Page