If what you’re looking for is a way to discover new music and you have some idea of the type of music you’d like to find (e.g. prog metal, sad songs, pop, etc.), I’d recommend creating a Pandora station based on a song or artist that represents that style. I’ve also discovered music by looking at the “Listeners also bought” section of the iTunes Store when viewing a particular album.

If what you’re looking for is reviews/commentary on music you already know, I know a lot of people like The Needle Drop (I personally am not a fan, but he does cover a lot of music across a fairly wide array of genres, so if nothing else it might be a good source for exposing yourself to a variety of music).