May I recommend that everyone interested in bookish matters, becomes a podcast-subscriber to 'In Our Time', a BBC Radio 4 programme. The website is here.
The appeal of it lies in the fact that you have three real experts on a given subject, who have a limited time to expound on it. So there is no dumbing down by having an intervening journalist trying to make it exciting for us silly people.
The archive has some great shows, but the latest is 'Heart of Darkness', which I know will be a subject close to many hearts.