The Discovery reading list currently includes the novels and comics which have included references to elements of the wider Lit-verse, or to each other. I also have a chronological list of every Discovery episode, novel, and comic here.
Since the Discovery reading list does not have a main storyline as many of the other series do, the light blue denotes the expanded storyline of the television series. Read any or all of these to go a bit deeper. Grey denotes every other connected story, regardless of overall continuity. As always, not every reference to every other story is mentioned, just the one I chose as most important to show the expanding Lit-verse web.