Usually published material here, and then rewrite it to fit my world. I have this fetish or compulsion really, for old modules, with great maps, like Ravenloft, love the castle, and Dragons of Despair, love the sunken city, and obscure resources like Midkemia Press, The Companions, Brotherhood of the Bolt, series, all have great art. The old school stuff really forces you to rewrite not just for the system, but style also, the idea of Monster ecology is missing in most of the older stuff.
I like to take a map or picture, then come up with my own story to keep my players guessing. I have played with to many old school players that have read the Dragonlance books and played the campaign, but I love to mess with their heads, when I pull out the old maps.