Rainbow Dash is a pretty good seed, starting you up between a swamp, a forest, and a desert. Copper is also pretty plentiful, as is Iron, but you're going to be traveling a little further for anything else. No sight of diamonds in any world I've set up and no real cave systems nearby. However, you pretty much start out with a ranch with both Cows and Pigs in abundance nearby, though chickens are rare and you have to travel far and wide for sheep. Fair number of rubber trees in the area.