Leather...
Wood...
Iron...
Stone...
*sigh*
I'm sick of it. where do i find diamonds and Gold? well that's not easy... but I'll show you!

Gold: Layers 0-20 i believe.
Diamond: Layers 0-12 i believe
Leather: obviously from cows...
Wood: TREES YOU DINGO
Iron: Layers er... 0-64?
Stone: Layers 64 (to make real stone put it in a furnace)

Most of this was figured out from Minecraftwiki.net i think. thats my source at least. Don't forget to subscribe! (oh and give me diamonds of course... :)