Creating and managing libraries

To create a new document library
on the top bar click create
then click on document library
on the new document library page, specify the settings and click create

To add documents to a library

open the doc library to which you want to add a document
click Upload Document, then click Browse
select the flie you wish to add, then click save and close to upload the document

Working with library settings

You can alter many of the settings within the library,
click on documents and lists, then select the document you want to access
on the left side of the page, under Actions, click Modify settings and columns
then on the Customize page, in General Settings click Change General Settings
From this point you can:

add a link to your library
require documents submitted to a library to be approved
add a column to a document library
modify a column
add metadata to a document