A blog is referred to as information or thoughts displayed by a writer for interested parties by publishing them on a website.
Writing a blog is very hard especially when you need to about a topic because it requires you to collect different information and put them together in a single document.
The answer to this question is vague, writing is a liberal art everybody applies his unique style.
Writing can just be done by any individual but the question that must be considered is how good the written piece would be.
You should not use many characters at the beginning of your book.