Exposition bad. Story good.
Seriously, the first rule of exposition should always be "Don't". Yes, you have information to convey to the reader. Yes, you are very proud of the world you have created. Yes, you want to show it off. Yes, the reader needs to understand all of the cool new words you are throwing at him.
Don't
From XKCD:

Exposition should be done in small bites, in context. Visual explanations are best. Casual dialogue comes next. Pedantic lectures should be avoided. Walls of text, while a favourite of poor fantasy writing, are something that let you know your whole concept needs trimming.
From the Great Muppet Caper:
Miss Piggy: [Lady Holiday has just given Miss Piggy the entire backstory for the movie] Why are you telling me all this?
Lady Holiday: It's plot exposition. It has to go somewhere.
If you start hitting me with too much exposition that is keeping me from enjoying the story, I quit. I go find something else to read. I like to give a web comic 20 pages. I am constantly amazed by how many of them are still doing exposition 10 pages in. It's not fun for the reader, and part of it feels like the author is just showing off the world, instead of telling me a story. I want a highly detailed world, but show it to me, don't tell me about it. Reference Robert Heinlein, G. R. R. Martin, or The Dark Knight Returns for examples of how to show me a detailed world without blatant exposition.
Work your exposition in gradually. Don't try to introduce your big concept and the exposition behind it all at once. Start out showing me a small story, then build it into your epic. It works better, shows more skill as a writer, and doesn't hit me with the gibberish all at once.
Eagle
(not trying to be harsh here)