2. Skull Mask: Give this to the Skull Kid in the Lost Woods.
3. Spooky Mask: Give this,during the day, to the boy in the graveyard.
4. Bunny Hood: Give this to Marathon Runner that is running around Hyrule Field.
5. Mask of Truth: Wear this maskand talk to the Gossip Stones. You will learn many valuable secrets.
The Gerudo, Zora, and Goron masks you can not sell but if you wear them and talk to people, they will give you interesting responses.