The Dark Lands

I've been working on my novel for almost 3 years now. It's nearly complete. I am getting nervous though. Being my first book, I'm not entirely sure of the best way to get it published. I know that there are some books out there to help first time authors find agents or get published (I'm hoping for some for Father's Day tomorrow) and I will read them. If anyone reading this has any advice, I would welcome it. Also, if you know any agents or publishers who work with the sci-fi/horror genre, let me know... :)