New to VoIP. Please help

Please read it. I need your help. Any suggestion is highly appreciated.

I am new to VoIP. Just completed graduation on Electronic & Telecommunication Engineering. I want to start professional life with Asterisk. How do I start it? Which will be the best to start with? Formerly I have much knowledge on PHP, HTML, CSS, jQuery.
I am using windows in my laptop and want to setup asterisk. Is windows better for this? I want to set up call center solution or asterisk system for clients. What is the way to do that?

asteriskdocs.org/

(All development work on Windows ceased many years ago, and that version ran in a simulated Linux environment (cygwin). If you wnat to work with Asterisk you need to learn Linux.)