You have to authorize your nook in ADE.
Then, with your nook appearing as one of the "libraries" in the left column in ADE (under All Books, Borrowed Books, etc.), drag the book from the right side of ade to the nook icon on the left side of ADE.
Then properly eject your nook from your computer, go to "my documents" on the nook, and check for new content.
Thanks soooo much I was competely lost! I just joined Netgalley so I was a complete space cadet.
I'm able to get the netgalley book ONTO my nook, but now that it's on there, I can't read it. The nook locks up every time I try to open one of the files. I'm wondering if I did something wrong.