Hello, I have some experience with similar kind of community projects (as you can see here:
http://www.librogame.net/index.php/down ... ibrinostri - don't mind that it's in Italian and it's gamebooks instead of plain adventures... the kind of development needed is similar) and I know that you really need to team up to complete the projects. Of course there will be just an author for each adventure (or maybe two), but you need a group of readers / testers / betatesters, somebody taking care of the images (better original but even the ones freely available in internet need to be cropped and adapted), a cartographer taking care of the maps and a final responsible that goes properly through the finished job and gives thumbs up. Of course all this work can be done by the sole author (maybe with the help of an editing template), but best results, as far as I can see, come from some level of collaboration. This also ensures that projects are not dropped when most of the work is already done or sidetracked all the time, as the group creates a positive reinforcement.
Personally, I don't think that I'm ready to be an author at the moment, but I can help reading the text (not really proofreading, as my English is pretty poor) and coming back with suggestions and observations. I may be able to help also with betatesting, if deadlines are extended enough.