Library Question

Hi guys i have just started learning flash so i am pretty new to this. What i woud like to ask you guys is if i create flash document called First.fla and create a black circle as a button say, add it to my library called button Black Button. As far as i know this is only available to this file ie First.fla. If i create another file called second.fla and i wanted to use the black button, how would i be able to share or view all the files created in library instead of opening up the First.fla and copy and pasting the button in my second.fla. Ideally i would also like to do view all the files created in my library so that i can just simply drag and drop. Hope that is clear.

Thanks