It's one of those truths that is so simple that its stark honesty is astonishing when it stares you in the face:  how much easier it is, to imagine the novel, than to actually give birth to Chapter One.  

Still, chapter one exists, however drafty it may be.  I have written more on this strange and elusive process here:

http://oneiran.blogspot.com/2011/04/beginning-novel.html