I didn't know what to expect from these novellas except that they occurred around ninety years before A Game of Thrones and featured a knight named Dunk and his squire named Egg.
First thing: I love the illustrations! They're reminiscent of the books I read as a kid, and I wished they were in color. They fit tonally with the stories and the illustrator picks great moments to highlight.
The novellas were originally written for anthologies, and so spaced out over time. Reading them one after the other shows some repetition in some of the exposition, and some similarities in the tales are more obvious, but those are the only issues I had and they were minor.
The stories aren't as grim or dark as the ASoIaF stories, so if you've been avoiding those because you don't want all the murder, pillaging, raping and child endangerment, these might be more your speed. Of course, this is still George R.R. Martin, so they're not fluffapalooza, but they are lighter in tone and Dunk and Egg are very sweet with each other.
Dunk is one of those rarities in Martin's writing: a genuinely good guy who stands by his convictions, does what's right and doesn't get horribly killed because of it. Egg is irascible and sheltered, but more than game for following Dunk around the kingdoms and proves receptive of everything Dunk has to teach him, whether it's how to care for armor, how to treat others better or how to hold his tongue. ... Ok, maybe not so much that last one. ;)
There's also still plenty of politics and intrigue, as these stories occur about a decade after the Blackfyre rebellion and the realm is still feeling the aftermath of it. Dunk might not be very good at avoiding getting tangled up in events, but he's so far proving good at getting out of them. :D