what are dunk and egg novellas? new to GRRM worlds.
I'm new to the series as well (didn't read it until after the TV show premiered), and I haven't read them (but I've seen other people talking about them online, which is how I found out what they were.) They're three novellas covering the adventures of Aegon Targaryen and Ser Duncan, a member of the Kingsguard.
Wikipedia has more information, but it's full of spoilers: