From watching “Younger,” the funny new sitcom about a single mother in her 40s who pretends to be 28 so she can land a job in publishing, I’m learning a great deal about selling books. For example, I knew that social media was key, but I didn’t know it had to involve nudity. On the show, Joyce Carol Oates uses “Topless Tuesday” to promote her latest release. Maybe I’ll co-opt the idea, such as with Wicked Wednesday or Murderous Monday.