Starting a Blog

It has been long time that I am trying to understand what kind of blog I can create. How it could be, what I should post ? Although the passing time helps, the best way to understand is just to start. I was planning to have categories of posts and organize almost everything of my studies, work and enjoyful stuff. However, I will post them as a mixture and see what comes out. So, I can plan next steps better after I have some experience. Now : "Hello World" :)