Talk to the children who will offer you a Slingshot training sequence (check your game's notice if needed). Once you've hit all the targets, look at the ladder in front of your house. Use your Slingshot to get rid of the Skulltula, then get inside your house. Open the chest to find the Wooden Sword! Get out and talk to the children again. Show them your swordsmanship skills (and thus learn all sword basics), then the monkey will show up! Follow the little group into the forest. Run straight ahead, cross the hanged bridge and go ahead again.
Keep on going ahead and look for some Horse Grass. Blow into it to call Epona, ride her and jump over the fence. Follow the left path and get off Epona at the crossroad. Read the sign and go left. Talk to the man, who will give you the Lantern! Light the pot by taking out your Lantern next to it, then put it away to save the oil. Go back to the sign and follow the other path.
Get rid of the Baba using your sword and get in the passage. Inside you can find some torches (they look like poles) that you can light by shaking your Lantern next to them. Get rid of the Keeses and the Babas using your sword and burn down the spider web by shaking your Lantern next to it. Stay on the path leading north to a glade. (In this underground passageway, you can find a chest containing 10 rupees if you head east). In the forest, fight or avoid enemies and head northwest (where a red dot is on the mini-map). Get rid of the Keeses and the Bokoblin (blue foe), then pick up the Small Key in the chest. Once again light both torches to the right and left of the chest to make a bigger chest appear. Open it to find a Piece of Heart!
Then head southeast on the mini-map, near the gate. Open it using the small key and go forward. Get rid of or avoid all the Bokoblins and keep going until you see a shop on the right. Fight yet another Bokoblin to get to Trill's Shop, which is selling red potions and some lantern oil. Go east, get rid of the plant and open the chest behind to find 10 rupees. To the north, you will see the monkey and Talo who got locked in a wooden cage. Get close and swing your sword at the cage to release your friends.