Items

Young Link Only items:

Mask of Truth - Allows you to talk to the gossip stones (those
stones that tell you the time when you hit them with your sword).
Complete Young Link's Trading Sequence.
Deku Sticks - Can be lit with a fire and then used to light
torches.
Bought in stores or obtained from killing Deku Baba's (the man-
eating plants).

Fairy Slingshot - Shoot enemies from a distance.
Found inside the Deku Tree in a room with a floating block that
falls when you step on it.

Boomerang - Stuns or kills enemies from a distance. Returns to
you.
Found inside Jabu-Jabu's belly. Find a room with all flying fish
in it and kill the flying fish to get it.

Fairy Ocarina - Plays magical music.
Given to you by Saria when you first leave Kokiri Forest.

Magic Bean - Can be planted in soft soil (See section 11).
Can be bought from a character near the entrance to Zora's River
for 10 rupees for the first one and then an additional 10 rupees
each one after that.

Adult Link Only items:

Fairy Bow - Fires arrows from a distance.
Found in the Forest Temple in the upper Stalfos room.

Fire Arrows - Exploding arrows made of fire that take 2 MP to
use.
After beating the Water Temple, stand on the island and face the
small island with two pillars on it that's across the water from
you (there's a plaque here explaining this) and shoot the rising
sun with an arrow. The fire arrow will drop to the small island.

Ice Arrows - Freezes enemies. Uses 2 MP.
Complete the Gerudo Training Grounds.

Longshot - Found in the Water Temple. It is just a longer version of the Hookshot.

Light Arrows - Very powerful arrows. Uses 4 MP.
Gained automatically when you have 6 medallions and return to Temple of Time.

Hookshot - Allows Link to grab things from a distance and pull
himself to them.
Found in the Kakiriko village graveyard. Look for the grave stone
with flowers in front of it on the far west side of the grave
yard, close to the entrance. Pull it to reveal a hole. Fall down
to talk to the gravedigger and you'll have to race him. Keep up
with him and he'll give you his hookshot.

Megaton Hammer - Destroys red boulders, smashes down rusted
switches, and other useful stuff. Can be used as a weapon.
Found in the Fire Temple in Death Mountain.
Shared items:

Deku Nuts - Stuns the enemy.
Bought in stores or found.

Bombs - Blows up enemies, rocks, secret tunnels, etc. Can be
thrown. Very useful.
Found in Dodongo's Cavern.

Ocarina of Time - Same as fairy ocarina. Needed for time travel.
Found in Hyrule Castle's moat after Princess Zelda throws it
there.

Lens of Truth - See invisible things and see through fake walls.
Uses magic. Also can look in the treasure chests in the treasure
chest game as young Link!
Play the Song of Storms in the windmill as young Link, and the
well will be drained. Go down the well and you'll be taken to the
Bottom of the Well level. Beat it to get the Lens of Truth.

Bombchu - A bomb that runs along the ground and up walls until it
hits something or a certain time passes then blows up.
Get 40 Gold Skulltula Tokens and then go to the house of the
cursed rich family in Kakariko Village and one of the children
will give it to you. Also can be won from the Bombchu Bowling
game and some other mini-games. At night there is a bombchu shop
in the back alley of the market when you are young Link. Can be
bought from a guy on a flying carpet in the desert.