The seed "stpatty" without the quotes spawns you in a forest. Go forward from your spawn point and there will be a village. There's a blacksmith house in the village (which now contain chests with items in them) and the blacksmith house is that house with the iron bars and lava out front. Go inside and there is a chest with 6 DIAMOND and 3 obsidian. There is another village quite a ways away with 3 more diamond in it, and the stronghold has a piece of diamond in a chest.

Hope this helped!