The House of Skulltula is located in Kakariko Village. Use the screenshot below to help you find the correct house. Approach the center of the room and a creature will drop down.
Speak to it to find out that it is actually a man affected by a spider’s curse. The objective of this side quest is to capture and return as many 
Gold Skulltulas as you can. Each time you reach one of the milestones listed below you can return to the house to obtain the listed reward:
The Stone of Agony is an accessory that causes the controller to rumble when you are near a secret area.
Just speak to the person who no longer appears cursed to received your reward.
The reward for completing the side quest and obtaining all 100 of 100 Gold Skulltulas is not that impressive. The reward is 200 Rupees that you can infinitely obtain making money no longer an issue for you, but the fact of the matter is that by the time you receive this reward, you are at the end of the game and Rupees are nearly useless.
In that sense the only true reward is the knowledge that you have fully completed the game (which is still something). Congratulations!
