The Graveyard
Visit the Kakariko Village Graveyard. A journal in the nearby hut will describe a hidden treasure buried with the gravedigger. Earlier in the game, when Link was young, the graveyard contained a patch of soft soil; in its place is a new grave. Move the gravestone to reveal a hole. Jump in.
Racing Dampe
Inside, you'll meet the ghost of Dampe the gravedigger, who will challenge you to a race through the hazardous maze beneath the graveyard. Follow him closely, avoiding the flames that fall from his lamp; be careful not to let him get too far ahead of you, as there are multiple paths through the maze and Dampe is your only way of knowing which is the right one. If you reach the maze's final chamber without losing track of Dampe, the gravedigger will reward you with the Hookshot.
The Lost Woods
Go to the Lost Woods and follow the twisting path leading to the Sacred Forest Meadow. If you don't already know the way, try this: walk as close as possible to each tunnel leading out of a particular place in the forest, and ignore any tunnels in which you can see a glimmer of white light. Follow only the tunnels that are solid black. When you reach an area where no tunnels are black except the one you came by, enter the tunnel on the right to reach the Sacred Forest Meadow.
The Sacred Forest Meadow
Navigate the Meadow's maze, defeating the spear-carrying guards by hitting them in the back with the Hookshot or by swiping them with your sword, until you reach a long flight of stone stairs. At the top of these will be an open area with a crumbled, inaccessible staircase. Use the Hookshot to latch onto the branch above this staircase, and Link will be pulled up to the platform at the top. From here, all you have to do is walk forward to enter the Forest Temple.