A bit of a hijack, but since we’re on the subject of Martin:
Do the Dunk & Eggstories add anything to the Ice & Fire canon or are they stand alone? I know they’re set 80+ years before the War of the Five Kings but was curious if there’s any insight into the history of the major houses, and a couple of characters (Aemon, Walder Frey) would be alive, though children.
I’m sorry, but I don’t think I want to know the answers to these questions myself yet. I’m only a few chapters in, and I think it’s possible that knowing the titles of later chapters could spoil something.
The answer is yes — they add something to the saga, and they stand alone. They are not prequels in the sense that you should read them first; you’ll probably enjoy them more if you read the books in the order they were published, rather than according to the internal chronology. But they’re good stories on their own, and you will learn more about Aemon’s relatives.