I'm working my way through the Sex & The Supremacy of Christ videos.
Here's a couple of really good resources on Song of Songs.
Andrew Jones on The Joy of Sex (BT briefing)
Note that this isn't Andrew Jones the TallSkinnyKiwi, but Andrew Jones of Grace Church Hackney.
CJ Mahaney on Sex, Romace and the Glory of God (video)
CJ Mahaney is well worth watching and listening to on this, and many other things. CJ is director of Sovereign Grace Ministries and former pastor of Covenant Life Church.