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. About halfway up the river is 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. Make
your way upriver until your get to the waterfall at the mouth of the
river. Then stand on the plaque in front of the waterfall and play
Zelda's Lullaby to make the waterfall reveal a cave. Jump over and enter
the cave to enter Zora's Domain.