Beethoven's Third Symphony, "Eroica" has quite the interesting story behind it, and is often cited as a landmark composition which separated the Classical era to the Romantic. It expanded tremendously on the symphonic form, and was many times longer than a comparable symphony by Mozart or Haydn. The excellent San Francisco Symphony -- at Keeping Score -- has a sensational Flash-based analysis of the history of the work, as well as a superb multimedia score-reading section. Additionally, composer W. A. DeWitt of Colorado has put together a thorough measure-by-measure analysis at his dedicated website. It's a tad long, but very thorough, and the piano reduction is written in! Highly recommended, most certainly!
Meantime, Chip is downstairs playing some piano --and doing pretty ridiculously well. He's a better sight-reader than I am I think, blast him.