How do I get to the windmill (presumably the dungeon where I will obtain the Pendant of Wisdom)? Link can't swim, and the island doesn't seem to be connected to anything. I know I'm missing something obvious here, but I can't for the life of me figure out what it is.
You need to go to Zora's Domain, and you can get there without swimming. Merge into the wall near the Zora who says he can't swim, and that will get you around the deep water and from there, Zora's Domain is nearby. Once you get there, go in and talk to the Zoras, who will ask you to do something for the Zora Queen:
You will have to get the Smooth Stone that the man you meet outside Zora's Domain stole (he will be in Kakariko Village, after you talk to the Zoras)
Once you accomplish that task, you will be rewarded with the flippers that allow you to swim.
As you presumed you will have to learn to swim which to link means,get Zora's Flippers.
She can be found in Zora's domain.
If you are playing 3DS find the witches house behind the eastern palace. Right by it is a person who can't swim. Merge in the wall behind him then go to the other side. Follow the path until you see someone come out of the waterfall and run you over. Go in the waterfall and ask about their problem. Then go to the village and head to the shop. If there is no new merchandise, (but if was at the shop when I played), find the guy that ran you over and get the stone back. Go back to the waterfall and give them the stone. You'll be rewarded with some flipper that will allow you to swim. Then cross that log and go to the waterfall. Done!
to get the pendant of power and wisdom using a glitche all you have to do is go to the outside of maiamai cave you can then merge into the wall. As soon as you re-emerge shoot a grapple hook towards where the entrance of the cave is. It should clip through the wall and grab an invisible pole. This allows you to explore the map. It is possible to reach the end of the game like this but to get the pendants you should head right until you see a chest, if you open it it will give you a red rupee. after that you should be able to open it again to get some monster guts. It will allow you to open it three times but on the third you will die for some unknown reason. When you respawn at your house you will be constantly receiving rupee to give you infinite rupees and you should have all the pendants. You will also have an item that looks like a potion that is called 'metadata01' However if used it will crash the game.