Organizing tools that I've found useful for organizing and writing books.
Microsoft Word outliner
Create topic headings for your book. Collapse the headers to see a high-level 'table of contents.' Expand individual headers to add detailed information as you work on individual sections or paragraphs.
Lately I've been using Google documents to collect information for a book I'm working on.
The advantages of Google documents are many. The two major ones:
1) All my files reside 'in the cloud' instead of on an individual laptop, netbook or computer, so I can use any computer to access my files.
2) Simplicity. Google documents is simple and easy to use.
The only real drawback I've found so far with Google documents is that it doesn't have an outliner function.
Inspiration visual organizing software
Inspiration is a 'hyper outliner' that allows you to arrange your ideas visually. You can then expand and collapse the headings and subheadings. The interface is designed for grade-school use, so it is simple and easy to use. (Buy the 3-pack if you have more than one computer. I've found transferring registration between computers to be a pain in the ass.)
Post-its on a wall
Clear a large space (a blank wall works) and stick 3x5 post it's to the wall. Rearrange the topics as needed. This is an extremely effective and low cost method of seeing the overall structure of a book.