This will be slowish for me. I am lucky enough to have a Kindle (plus the Android app) and enough disposable income to buy a book whenever I feel like it, so I had the book on my phone within seconds after the choice was finalized. But I’m certainly happy to wait until everyone (including the broke and those out in the Book-Desert Hinterlands) lays hands on a copy. (And hey, you broke folk: if ten quid is all that stands between you and the book, PM me and I’ll get an Amazon gift card out to you or something. Your participation is far more valuable to me than the dollar equivalent of a lunch at Taco Bell.)
If everyone had the book now and everyone read at my speed, my vote would be to discuss along the way, like every chapter or so. I started reading last night, and I’m already on Page 20, or about 6% of the way. I know there are chapters, since the book starts with a big ol’ 1, but I don’t know how many chapters there are since I’m still in Chapter 1, and the Kindle edition at least has no table of contents, and I am somewhat loath to flip ahead just to see where the 2 is. This is the kind of thing that sometimes makes me prefer dead trees. 
So anyway, if we’re going to have to take up to three months to do this, I’m going to delay my reading until just before each deadline, to keep my memory fairly fresh. @Miasm 's re-reading approach sounds sensible to me, but I almost never have patience for re-reading a book until I’ve forgotten what happens in it.
In a perfect world, where you were all exactly like me (okay, for a given value of “perfect”), I’d suggest we’d start once everyone has a copy, discuss every chapter upon having read every chapter, and (based on a totally wild-guessed chapter length of, say, 30-50 pages), schedule one to two chapters a week. Of course, this may be wildly overoptimistic in terms of how fast people comfortably read and how intense they want the discussion to be, but anyone who paid attention to Badass Dragons of the Wasteland knows all too well how wildly overoptimistic about deadlines and scheduling I can get.
Maybe someone who has already read the book can suggest an appropriate size of bite-size pieces to read and discuss? Someone who is familiar with the pacing, and the density and subtext and all that stuff? I just think, IMHO, three months might be a good length of time to digest and discuss something like Infinite Jest or Gravity’s Rainbow, but might be too leisurely a pace to keep us all focused on this relatively slender volume. But that might just be me, of course.
Also, a side note: earlier in the book-nominating process, I mentioned that we could read Johnny Got His Gun, the 1939 National Book Award winner written by Dalton Trumbo, if only because I have half a case of paperback copies which I can mail out to interested readers who might otherwise have trouble securing a copy. That offer still stands for our next book, if enough people want to read it. (I, myself, somewhat shamefully haven’t read it yet, though these books have been in our house for nine years now. I did see Metallica’s One video, so at least I know the important plot points from the 1970 movie.)
And finally, when it comes to decision-making, I think we can have all the discussion here and only use Loomio when we’re ready to put things to a vote. (The Loomio-inaccessible can vote here and we can manually add their vote so they retain a voice.)
