Books are especially good sources for literature topics, including Shakespeare. They are more comprehensive than background sources, yet aren't usually as challenging to read as scholarly journal articles:
The HACC Library also has a large collection of Shakespeare related print books. If you are able and willing to get to a physical campus, then you can request and pick up books that interest you.
To search for print books in the HACC Catalog, use the dropdown menu on the left of your search screen to switch "everything" to "book collection."