In general, books for Social Work are located in sections HQ-HV in the Library of Congress Classification System.
Helpful books on clinical aspects of Social Work may also be shelved in sections RA-RC.
Are you looking for the DSM-V? Molstead Library keeps it at the Information Desk for quick reference.
Submit an InterLibrary Loan request! They are free and allow you to borrow materials from other libraries across the country.