[ThirdSight]

Eragon and all of the Lord of the Rings, including the Hobbit, had maps of the country in the fronts of their books. They still explained layouts, countrysides, etc. because a map only gets you so far. Hell, play any fantasy based MMO with a map, and compare it to the world you're playing in; you'll notice a great deal of detail missing from the map. Maps work for reference only to the reader, everything else is on you.

You've got a point, it's a good trick to play off something important to explain it later, enticing the reader to keep reading. But then, as I mentioned earlier, why was it trying to be sold, if it's that important? Make sure motivations are solid throughout your story, otherwise your reader won't be able to connect, even on the basic level of things.

I believe it's Moby Dick that has an entire chapter devoted to describing only one thing. Boring to the average reader, yes, but to the literary community, that's powerful as hell. And all of it was important, not just jibberish to keep things going. As a fantasy writer, your duty is to bring the readers along for the ride to a world that doesn't and will never exist, which is the whole point of presenting a reader with a fantasy novel in the first place. Therefore, half of your task is to describe in greatest detail the world these people inhabit, and half is devoted to enticing your reader to stay in it. You don't have to go as far as Tolkein did in creating a language, massive history, dozens of races, each with their own history, etc., but you do need to invest in it. You're the creator of this world, and if it's boring, not even your characters will want to be there.

Histories are supposed to be complicated, and half of the time, the characters in the novel are coming to terms with the repercussions of what has happened in the not too distant past. However, just because a history may be long doesn't mean you have to devote a whole chapter to exposing it. The sum of the history of 1984 isn't divulged in a chapter or two, but told through the people that live in the society, and the government's effects on those people. Different genre, but you get the point: if the cities in ruins, was it because of a war? Are there any people banding together in tribes to survive? Or has there been a massive economic crisis, benefiting those in power by slandering the freedoms of those less fortunate? This all adds flesh to your characters; your characters aren't defined by their time on screen alone.

It sounds like you got some work, but you know that, and it sounds like you're letting on more than you're revealing, which may be ok for the reader as a whole, but it's a fine line to walk. Keep at it.