Christian here too, so I don't know the Jewish position on that book. I personally see it as an illustration of the love for a husband for his wife, (which pictures Christ's love for the church inasmuch as the church as his bride) but primarily about the joy/beauty of married love. There is a fair bit of sexual suggestion in it (I think) and some parts that are difficult to understand in context, and I always wonder how much Solomon understood about marriage and love, since he had I think 300 wives and 500 concubines, or something like that. I mean, really, what did he know about a deep commitment to one woman?
No, I've never heard a sermon on it either. Can't see too many ministers getting through that one without trouble. Not appropriate for all ages, I'd say. But I've heard a couple of lovely songs (look for Arise My Love, by Michael Card.)