I highly recommend all writers read Stephen King's On Writing. Not only does it cover common mistakes writers inadvertently make, it also covers areas of writing my creative writing professors in college didn't even mention.
On Writing is also available as an audiobook, narrated by Stephen King himself. In addition to his notes on the writing craft itself, I enjoyed the tale of his personal role to publication and the struggles involved.
Christopher Vogler's The Writer's Journey has long been a staple for screenwriters. But I believe it works well as a reference for novel writers, too. In it, he breaks down the entire journey, from the ordinary world to the inmost cave and beyond.
Even though we write because we love it, we must not forget that writing is a business like any other; and we must protect ourselves through legal means. So when you've completed your manuscript, you should copyright it before submitting it to agents and editors or before publishing it yourself.
If you plan to go the traditional route and are looking for a literary agent, the Association of Authors' Representatives is a professional organization with a searchable data base of member agents who must subscribe to their canon of ethics.
The Writers Market is another good resource for writers who are pursuing traditional publication. Each year's guide contains everything from advice on writing queries and proposals, to the contact information and current needs and submission guidelines of agents, consumer magazines, and book publishers.