I just beat the Castor Wilds area, and I have the Wind Ocarina and everything...

Okay, you need to "warp" to lake hylia with the ocarana of the wind, the stay on that platau place and become minish. Go into the mushroom house and just talk to the minish guy inside there. The become big again and warp (or you can walk but thats abit slow) to hyrule, then the library should be open. You need to return all of the books to the library girl, on the left. The first one is in juliettas house - go inish in romeos house (i think thats his name) then go up his chimeny, go along the wooden plank, connecting the two houses, and go down juliettas chimeny. You need to climb on the bookcase and just push the book off the top. Then go big again in romeos house, pick up the book and then return it to the library. The second book is in that mad scientist guys house in the west of town. You need to become minish in the wooden house with all of the builders in it and go into the mad guys house, then (if you have the power braclets, if not then ask again I have nothing better to do than to answer these really!) push the two bookcases towards the fireplace and walk up into the rafters of te house. Then multiply yourself and stand on the book wit te other minish guy. Its should fall down and then when you are big again you can retreive it from the house and give it to the librarien. The third book is all the way in lake Hylia cheaked out by the Hyrulian mayor; you need to go to the area in the minish woods where syrups hut is and you have to go into the mole cave, and find the ladder in it. Go up that ladder and youll be in the lake. Go to the bush that sparkles by the lakeside cabin and run into it with your pegesus boots. It will turn into a stump that turns you minish. Enter the hut from the back when minish and you (i think) push the book off the top of the bookcase. Then you will have all of the books; This means you will have the ability to get to that minish elder in the library. He will drop you into a hole in his floor and just search around in the cave until you get flippers. This will allow you to get into the temple of droplets to get the third element.

I hope this rather lenghthy explination will help you and answer your question, I'm sorry if it is not what you ment! Hope it helps!