My system for rating books comes from my personal option. Any books that fall into my rating system is solely based on my personal preference and is realitive. I try to find the best in every book I read and review as often as possible regardless of how terrible or amazing each book is.
"Don't waste your money."
"Wouldn't recommend it to a friend."
"Get it from the Library first and see about buying it."
"I really enjoyed it! It's worthy of a place on my book shelf."
"Loved it! Going to tell all of my friends to get their own copy."
~Kelsa