If you want to follow a blog written by someone in the publishing industry, Agent Sydney is a great choice. Responding to questions from authors, she tells it like it is.
Yesterday's post, Dude, where's your punctuation?, is a wake-up call for anyone who thinks that agents and publishers will overlook bad grammar, punctuation, and style if the story is good enough. Long story short, they won't. If you want to succeed, you have to know how to write clearly in your language of choice.
Trying to write a good novel without a grasp on proper grammar and punctuation is like trying to paint without knowing what size brush you need or how to hold it. If you find yourself in this predicament, I highly recommend you enroll in a Grammar and Rhetoric class at your local community college. Artists take classes to perfect their technique. Writers should, too.