C-SPAN founder Brian Lamb has always been a strong proponent of literature in an age in which television is dominant in the lives of most Americans, and he has regularly used his family of networks to promote books and authors. But this weekend, Lamb’s self-hosted and much-admired series “Booknotes” comes to an end on C-SPAN’s air. The decision to end the series was Lamb’s own, but he has no intention of leaving behind his passion for reading, or his efforts to call attention to deserving authors.