if you really wanted a better answer I would say to supply a little more detail. Is it absolutely necisary to supply all this information in the begining or for that matter even a good idea? As someone else explained presenting as little as possible in the begining and finding excuses throughout to present small bits at a time is generally more usefull. Also keeping an audience in the dark, particualrly in science fiction, and treating them as if they should know the facts can engross you faster into a storyline. Then if you really must clarify details, having characters discuss poitns or have flashbacks or simply think to themselves works well. Robert Heinlien for example loved to write about social problems in his stories but being of an engineering background he insisted on having as much pratical science as possible in his stories and he damn well wanted the reader to know the trouble he went through thinking some stuff up. Most commonly he’d use the newbie concept. Introduce a newbie charachter that needs to have things explained to him by the more experienced members and the reader gets the lecture at the same time. For example a good film use of that technique in a storyline similiar to yours would be the film Red Dawn. The filmakers actaully put together a painstaking and realistic scenario to explain how this world war three could come about. In fact it had been supplied by a former secratary of state and based upon alternate timeline prodections of geopolitical events formed by the U.S. military. However most of the information wasn’t needed to get the action rolling, as the audience ddint need to know anymore then the teens the story focuses on. Later though just so that we wouldnt think that this plot was completely off the wall we get introduced toa downed pilot that looseley fills in the kids with details leading up to the war. Just enough mind you. In the end the producers left most of the information out simply because it was directly pertinent to the storyline. In fact ever wonder how much gets left on the cutting room floor by any science fiction author? Ever wonder why they often write more then one story within the same “universe”? You could also, I suppose, if you really needed all the information to presented right away, have an early charachter discover the information (even if they allready know it) through finding a journal, propaganda film, text book etc. vica versa an old *** popular in the eighties was a non-essential charachter presenting the buildup to the storyline then having an “accident” murdered etc, or as reflection from their current point aka. “at this time this happened the world was etc and we were etc untill the day of whatever when the blah blahs atacked, but i’m getting ahead of myself. I suppose it really began when….” this kind of reflection can be done in a cold narritive but also spiced up a bit more like “we should of seen it coming. When they enected blah blah blah we should have seen the signs. At that time the federated blah was ruling. Myself I was only a and doing whatever and what have you” By throwing a little sub story with your narritive as a complete chapter or two it can keep it from sounding like the intro to a star wars movie. Good luck.

Ah yes, the dreaded expository bloc. Read more Arthur C. Clarke – he writes science fiction primarily to get scientific ideas across, and handles the problem better than most. Robert Forward does pretty well at it, too.

You don’t.

Whittle the info down to the essential 3 or 4 facts that get the story going, then introduce the other facts at appropriate times in the book.

Otherwise, you’ll bore the reader.