The following is a compiled list of all the extra things you can encounter in the game.

Mushrooms - Can replenish 10% of Frodo's health.
Crams - Replenishes 30% of your health.
Lembas - Replenishes 100% of your health.
Miruvor - Replenishes 100% of Gandalf's spirit.

Longsword - The first blade Aragorn has.
Anduril - The blade Aragorn acquires (Rivendell).
Walking-Stick - The first weapon of Frodo.
Sting - The second weapon of Frodo (Rivendell).
Westernesse Dagger - Frodo's temporary weapon.
Glamdring - Gandalf's permanent sword.