One other suggestion (which you may have followed already) is to spend some time reading the Scrivener forum (http://www.literatureandlatte.com/forum/ which is a crimper's box of delights...

Of course there's a great deal on Scrivener itself. There's also an entire board on "Other People's Software" where many of the applications already mentioned here, such as DT, Curio and Tinderbox are discussed in detail, plus some others including utilities. And there's even a thread currently running discussing what software to put on a "writing" Mac laptop.