The biggest hurdle we have is making people aware that the book exists. I started promoting my book about a month before its publish date (next week). If you didn't do any pre-release promo, you'll need to start now. Without knowing what you've done yet, I'll just direct you to two of my blog posts where I've listed some things to get you started:
http://fantasyauthor.blogspot.com/20...ing-tip-1.html
http://fantasyauthor.blogspot.com/20...ing-tip-2.html
I'll get the other tips I have posted soon. Hope this helps!