Assuming you are asking how to get started here, first of all, don't think of it as a blog. Think of it as a place to add valuable content that people are searching for on places like google, yahoo, or bing.
Then think of why you are here. Are you here for creative, social, or to make money? If you are in it to make money I would consider starting at the hubpages learning center. It pretty much answers every question you could have. http://hubpages.com/learningcenter/contents
Also consider learning how to use the Google Keyword tool so you can learn what people are searching on whatever topic you are interested in writing about.
Follow the rules of writing, such as don't copy and paste or quote large amount of words written by someone else (this includes the bible and other materials already on the internet). Always post original content. Write at least 700 words using separate capsules (you will see this once you hit start a hub and give a title). Use original or public photos. Consider adding polls or ratings.
Good luck and welcome to HP!