The first thing you will find under the spawn is vein of coal, keep digging straight down until you fall down into mineshaft. This is large mineshaft and quite complex. Have lots of iron and coal in the mineshaft but gold and diamonds quite hard to find.
Minecraft PE Seed: heheyhey – Island Spawn
In this Minecraft Pocket Edition seed you will spawn on an survival island. On the surface of the island have some trees and sugar canes is only real resources can be seen. But if you digging straight down from the spawn you will find some ores.
Seeds : heheyhey Work in PE ver0.9.0+