Arrows

The arrows are required to shoot the bow. One arrow costs one rupee to shoot.
Bait

The bait is used to distract enemies from you temporarily. It’s good for rooms filled with enemies.
Bombs

The bombs are used to blow up walls that lead to secret passages. It can als be used to hurt many enemies at once, or a boss.
Boomerangs

Boomerang: The boomerang is used to stun stronger enemies (I.E.: Dark Nut), and used to kill weaker enemies (I.E.: Keese).

Magic Boomerang: The Magic Boomerang is an upgrade of the boomerang. It goes twice as far as the regular boomerang.

Bow

The bow is used to attack enemies from a distance. It costs a rupee for every arrow you shoot, though.
Candles

Blue Candle: The Blue Candle is used to light up dark rooms. It can also be used to burn down bushes to reveal secrets. It can only be used once per screen.

Red Candle: The Red Candle can be used more times on a screen than the Blue Candle. It does the same thing as the Blue Candle.

Clock

The clock freezes all the enemies on the screen and makes them harmless. No enemies will appear after you kill the frozen enemies until you exit the screen.
Compass

The compass is usually obtained by killing all the enemies in a certain room. It tells you where the Triforce Shard is; this also reveals the location of the boss.
Fairy

The fairy is used to heal all of your health. Enemies occassionally drop fairies, and there’s a hidden fountain that has one.
Hearts

Recovery Heart: Occassionally dropped by enemies, these hearts heal one full heart of yo0ur health.

Heart Container: A Heart Container adds one full heart to your current health. They can be found in hidden places and after defeating bosses.

Key

The key is used to open many dungeon doors. If you collect enough, you can have a lot of extra keys. (The extra keys are helpful in later dungeons, where getting keys becomes perilous.)
Ladder

This ladder is used for climbing across water. It can only go across one square of water, though.
Letter

The letter is used to get potions from several “old ladies” across Hyrule.
Magic Book

A book of magic. It simply makes your Magic Wand so that, when it hits a target, it bursts into a flame.
Magic Wand

This wand shoots out a beam similar to the Wizzrobes. It’s not very strong, though.
Magical Key

The Magic Key is used to open any door in Hyrule. Unfortunately, the key is found near the end of the game.
Magical Shield

This shield deflects projectiles a lot better than your first shield. It can be bought in several places.
Map

The map provides a look at every room in the dungeon you are in.
Potions

Blue Potion: The Blue Potion heals your life completely, but have only one use. When you buy two Blue Potions, you get a Red Potion.

Red Potion: The Red Potion lasts for two uses instead of one.

Power Bracelet

The Power Bracelet allows you to move some rocks in Hyrule. To find it from the graveyard, go right two, up one, and right one. From the start: go right one, up five, left one, down one, left one, up one, and left one.
Raft

This handy floatation device lets you reach a dungeon and a Heart Container. It obviously floats across water.
Rings

Blue ring: This ring, priced at the Special Shop for 250 rupees, halfens the damage you take. It’s a good deal!

Red Ring: The Red Ring turn all incoming damage to 1/4 the normal amount. You get it late in the game, though.

Rupees

Flashing: The flashing rupee equals one rupee. This item is found by killing enemies or in some secret locations.

Blue Rupee: The Blue Rupee gives you five rupees.

Swords

Wooden Sword: The Wooden Sword is fairly weak, but is reliable nonethless. It does little damage and is almost useless later on in the game.

White Sword: The White Sword does twice as much damage of the Wooden Sword. You are required to have six hearts to get it.

Magical Sword: In order to get this sword, you need fourteen hearts and a Power Bracelet (to move the grave it’s under). It does four times the damage of the Wooden Sword.

Whistle

The Whistle makes it easier to return to dungeons you’ve already visited as it warps you after it summons a whirlwind. It also hurts enemies such as Digdogger, or Pols Voice.