Many authors swear by Scrivener. I tried the free trial and I hated it. It doesn't work for me. I like word, even though everyone else seems to hate it. Granted, I've only written one book, and an unpublished book at that so my book-writing experience is next to null, but it worked well for me. What I do like, though, is a supplementary software called Storybook. While there is the option with Storybook to write your book in the software, that's not what I use it for. I use it to keep all of the information I need at my fingertips. I have my outline in Storybook, I have my character profiles, my plot questions. My world building information, which is vital to a fantasy writer, is kept in Storybook and backed up in Evernote.
Storybook has a feature called Strands. Each Strand can contain an entire novel, or your notes on anything you want. I usually keep the Default Strand for keeping information about each chapter, an Outline Strand for my outline and any notes I need to make on it, a Notes Strand for any notes that don't fit anywhere else, a World Strand for the world I'm building, and a Research Strand for noting where each piece of research comes from and what information I plan to use. If I read a great piece of folklore from Alabama and want to incorporate it, I'll make a new 'scene' in my Research Strand, type in the information I'm keeping, add the source to the notes section, and it's right there. Any new document within a Strand is a 'scene' though not everything is an actual scene. What I love about Storybook is that you can also tag each 'scene' with which characters and locations are involved.
The software also keeps track of characters, locations, items, chapters, parts, and tags. I create each character in the character function, fill in all their details, and tag them in the correct spots. When I need to, I make notes about them in either their profile's notes section, or in a Strand and tag them. Same with locations. I have yet to need the items function as there are no objects of such importance in my book. Tags allow you to focus on the multiple elements in a book, like drama, romance, violence, etc. You can tag each 'scene' with which element it reflects.
Finally, another feature I love is the Ideas panel. If you have an idea but don't know where it belongs you can click the lightbulb on the top toolbar and it pops up with a little dialogue box for you to type in your idea. Then, to view any ideas you've had, go to Charts And Tools, then click Ideas and they're all there.
For more information, check out the Storybook developer website here.
I've been considering trying out writing the book in Storybook for Camp Nano. I'll keep you updated.