I looked at various programmes that you can get, some free, some you pay for, but I decided just to use a word document. I have the navigation page on all the time when writing as it is really easy to flick through chapters, as you will find yourself wanting to add/remove bits as you go along. If you choose heading style 1 (see those squares at the top of the bar?) that will automatically put them in the navigation page. When you have finished a chapter, just right click on the ‘Chapter 1’ in the navigation pane and you can add another chapter. If anyone wants more info and will use it let me know and I will try and do a video of it!!!
If you click on the tidy little open book symbol bottom left, this bring up the ‘Editor’ this looks like it will be really useful when it comes to editing the book, might not be quite a good as an expert! but I certainly think it will be useful to those of us that it doesn’t come as second nature to edit our work (me)
Hope that helps, if you need any help, leave a comment and I will try!