Zora's River:
Use your bombs to blow up the boulders in your way. You can make use
of the chicken at the beginning of the river to get to a few heart
container pieces. Also this is where you meet the guy that sells the
magic beans which you will need. About halfway up the river are some
frogs. Play your songs for them and they'll give you money. If your
money's full go buy some magic beans before playing another song for
them. When you play all 6 non warp songs, they'll give you a heart peice.
Make your way upriver until your get to the waterfall at the
mouth of the river. Then stand on the Triforce symbol and play Zelda's
Lullaby to make the waterfall reveal a cave. Jump over and enter the
cave to enter Zora's Domain.
Zora's Domain:
The first thing to do here is get an empty bottle and find the little
fish floating around in the shallows near a circle of stones. Use the
bottle to catch one of the fish. You'll need it later. Now head up
to the top of the mountain in the middle of the domain and you'll see
King Zora. Before doing anything else, take this opportunity to use
one of his torches to light a Deku stick and quickly run down and light all
the other torches in the domain, including two hidden behind a
waterfall. This opens a few things up for you, like a heart container
piece. Go back to the King's room
and talk to him, then head left from his room and find the diving
game. Win at the diving game and you'll get the Silver Scale, which
allows you to dive deeper. Now look for an underwater doorway at the
front of the mountain. Dive down and go through it and you'll pop up
at lake Hylia. Swim forward a bit and you should notice a bottle at
the bottom of the lake. Dive down and fetch it. Then swim back
through the tunnel to Zora's Domain. Bring the bottle to King Zora
and show it to him (press C when Z Targeting him) and he'll take the
note out and move out of your way. Now take the right path to get
behind him and enter Zora's Fountain.
Zora's Fountain:
Ignore the big fish (Jabu-Jabu) for now and instead swim behind him to
the southern part of Zora's Fountain to a small island with a tree,
some bushes, and two boulders. Put a bomb next to the gray boulder to
blow a hole in the wall and get the Farore's Wind spell from a great
faerie. Now swim onto the platform by Jabu-Jabu's mouth and walk up
to him. Use the bottle with the fish in it to offer the fish to
Jabu-Jabu, thereby making him open his mouth and swallow you.