If you're not familiar with it already then I highly recommend checking out Songs for Drella. Lou Reed and John Cale put aside there differences after Warhol's death to record something of a eulogy for him. It offers an interesting perspective on the early days of the Velvet underground, their relationship with and subsequent falling out with Warhol, and Warhol's life in general. It's beautiful, haunting, and heartbreaking.