The answer is in the question, Varrock Castle (Palace).
You just said it, Varrock Library, Inside Varrock Castle.
The Varrock Castle is east of the Varrock bank or northwest of the Varrock General store.
In varrock east of the castle.
Go down the manhole east of the Castle.
The taskmasters for Varrock are Reldo, in the castle library, and Rat Burgiss, near the gap in the Al-Kharid fence.
You can find sheep sheers at general stores common GS are in Lumbridge;next to the castle,And in Varrock; teleport to varrock...
He is located in the church near varrock castle east side
You can buy buckets from general stores or from the grand exchange located in the north west corner of Varrock.
Edgeville or behind Varrock castle.
Dummies are located North of Lumbridge castle and East Varrock in a house across from the bank.
green dragons, or pick up bones that you find in varrock castle about 80gp each