If you allow cheats then you can do lots of things:
Cheats:
/gamemode 0 switches to survival
/gamemode 1 switches to creative
/gamemode 2 switches to hardcore
/gamemode 3 switches to adventure
/give gives you things
/freeze freezes mobs
/spawn spawns mobs
/help gives you more commands
/tp teleports you

Hints and tips:

Get wood and make sticks by ~ = wood @ = planks # = sticks

~ = @ x 4

@
@ = # x 4

@@@
# = wooden pickaxe
#

@
@ = wooden sword
#

@@
# = wooden hoe
#

@
# = wooden shovel
#

@@
@# = wooden axe
#

[ = cobble stone ] = iron ingot { = golden ingot } = diamond

Do the same with wooden planks as with cobblestone, iron ingots, golden ingots and
diamond.

+ = wool

.
@@@ = bed

( = string

#(
# ( = bow
#(

[[[
[ [ = furnace
[[[

@@@
@ @ = chest
@@@

@@@ = wooden pressure plate

[[[ = stone pressure plate

¿ = melon slice

¿¿¿
¿¿¿ = melon
¿¿¿

) = torch

* = pumpkin

*
) = jack o lantern

##
## = wooden door
##

]]
]] = iron door
]]

@@@
@@@ = sign
#

# #
### = ladder
# #

Hope this helped!

If your looking for emeralds then look in the extreme hills biome.