There's a Star Wars podcast I heard a year or so ago, called "Coffee with Kenobi" and they interviewed James Luceno(who wrote in both the prequel era and post rotj era, and in the new canon. His most famous SW novel is probably "Darth Plaguies). The interview is about his book "Tarkin." I was going to transcribe the pertinent bits of conversation, but it turns out, it's all in the first 7 minutes.
They ask him about the process of putting together a novel with Lucasfilm under Disney, and how things have changed under the story group. He says nothing's changed, there's a few new faces at the story group, there always was a story group, the process is the same and very casual, etc, etc.
He's a really nice guy and a good author, and it's a really good interview. I recommend
Lucas himself was mostly hands off with the books. There are exceptions, like he was more heavily involved with the larger multi media project stories, such as "Shadows of the Empire," or the movie novelizations, or unique novels like "Darth Plagueis," but there was a team of people working together, and with authors, to create stories in a continuity.
