A blog for me is more on making opinion based on your personal knowledge on the topic you want to discuss. You make blogs like dairy on line about your thoughts that you have gathered thru learning or experience and that it is important that you can support your ideas or claims from your own stand point or perspective. You make posts that somehow create general interest that will draw people to read your blog. You can make research or study to support what your doing. You should read other blogs too to get ideas on how they did it.