What is Blog ? How can i create a Blog myself?

As best as I understand what a blog is, it is very simple. Did you look at the relevant articles in this web site? I see some listed under "Our recommended articles" at the right side of the window but there are probably more that will help.

Blog = Web Log
It's like writing notes or sharing your ideas. You can start your own blog by clicking on Blog link of his website's home page.