It's actually kind of fun to post things out of chronological order, and think about what you've already revealed to your readers and kind of play with that a little bit. In some ways, fanfic is that way already, because your readers already have a good grounding in who the characters are and how their world works, so the fun thing as a writer is to play with that -- if you already know who Rodney is, a story about Rodney's childhood is completely different than if you first meet this sullen little kid and don't find out what he's like as an adult until later. When you're writing a series out of chronological order, each additional part becomes sort of a riff on what's already been established, rather than building a logical progression of events (if that makes any sense).