After receiving the blue chicken from the woman you helped gather her chickens for, you take it into the lost woods and give it to the man who hates people.  It was his chicken and he takes it and he gives you 
something in return... I think it\'s a mushroom.... well, you take it to the old lady in a potions shop. you get to her by taking one of the chickens and flying over the fence in Kakariko Village by the well. 
You are timed through all of this so it helps if you use Epona to go faster. After you give the old lady the mushroom, you receive some sort of potion that you have to return to the man. You are timed
again to get to the man and give it to him. But when you go there, instead of the man there will be  a little girl.  You give her the potion thing and she gives you a saw.  You take the saw to the Garudo place.  There will be carpenter men there and you give the older man the saw becasue it is his. He will give you the broken knife thing that you have to bring to the Big Goron.  When you do so, it is his work, so he trades it for a letter saying when he is finished making a sword for you, you get it. If you walk to the 
lake and back it will be done. Then you recieve the Biggoron sword.

Hope that helps you out some.

Luv yas!