It's an interesting question Swaeft, and one that is likely to have a lot of different answers depending on each writer's writing style and attention to detail. Some people just want to move the story forward, some want to build a world behind it, some have incredibly in-depth characters, etc. For a narrative AAR, I'd imagine (maybe even hope) that one spends at least a couple hours per post (unless, of course, the posts are very short). For creative writing, that might be very different, as the amount of characters and type of story may require far more or less.
For myself, I think that all told an AAR update takes me about 7 to 8 hours of proper work, with a few days of passive thinking. The breakdown would be as follows:
I start with probably about an hour of actual research (looking at maps, reading a bit about things that will be important, etc.), after which I just think for a day or two, letting things roll around in the back of my head. Once I have a good idea of what needs to go in I take about 3 or 4 hours for writing, split over a few evenings (and a few glasses of Scotch
). When the writing is done I then transcribe it (I first write by hand, as I find that to be really helpful for creativity), which usually takes about an hour. Then I read over it, looking for issues, making small tweaks, and improving things. That takes about another hour. Then I carefully read it again out loud, just to be sure I haven't missed anything (another half hour). Then I put together the post, which is roughly another half hour. All told, that adds to about 8 solid hours of working (more if the post is longer or makes more use of history/geography, as that adds to research time), but with a lot of hours between where I let things stew. For me, that stewing is important, as I think one of the biggest things that makes writing good is letting the story lead you, rather than the other way around, and for that to actually happen I need to think about who my characters are and what the situation would lead them to do. That can take time, and is usually best accomplished during walks with the dog.
Aside from all of that, there is then the question of whether I'm including an image or map to the mix. That can lead to another couple hours, but is dependent on what the writing then requires.
So that's my method at least.