Hi! It's stated on the rewards page (amongst a bunch of other paragraphs so it might be easily missed):

Quests can be submitted once the primary objective of said quest has been completed. For example, if you're gathering strawberries, once the strawberries are picked in the thread, it can be submitted for rewards.

The numbers are more or less up to player discretion. If you only want 1lb of wool for example, then you would add only that many Bones.