The Ordon Shield is the first shield Link receives in Twilight Princess. The shield has a very simple design of what appears to be goat horns in the middle of the shield. This design closely resembles the Light Spirit Ordona who also takes on the form of a goat. The Ordon Shield is made out of wood, therefore it breaks when in contact with fire, and once it breaks, Link cannot get another one. If it burns, Link can go to Malo Mart in Kakariko Village and buy a Wooden Shield, a shield that houses pretty much the exact same properties as the Ordon Shield, for 50 Rupees. The Ordon Shield also shares many similar properties to the Deku Shield from Ocarina of Time.
It can be acquired after Link has escaped from the jail in Hyrule Castle. Midna, the character who helps Link escape, tells Link he should get a sword and a shield before heading out to rescue the children of Ordon. Link has to steal the shield off the wall from Jaggle's House in Ordon Village. Link won't be able to use the shield right away because he is in wolf form. Link is only able to use the shield after restoring the light back to the Faron Province.
When Link is in Hylian form, the shield can be used by holding the Z-button in the Wii version of the game. While holding Z it blocks almost all attacks from the front. After Link has cleared the Twilight from the Eldin Province, he can go to Malo Mart and buy himself a Hylian Shield for 200 Rupees. This shield is resistant to fire thus it won't burn on contact and is the best shield within the game.