Valve held a conference for developers last month called Steam Dev Days and, as promised, a number of sessions have since been uploaded to YouTube. In some cases, presentation slides are also available. While there's certainly a fair bit of technical talk to be found here, if you're here reading this now, you'll be just fine watching this stuff.
Some of the talks that stand out to me as someone who isn't a game developer are: "In-Game Economies in Team Fortress 2 and Dota 2," "Marketing Your Game," "Community and Communication in Games-As-Services," "What VR Could, Should, and Almost Certainly Will Be within Two Years," and "Is Early Access Right for You?"
Find the links to those sessions and more at the official Steam Dev Days site.