Booth, Wayne C., et al. The Craft of Research (e-book). 4th ed. Chicago: University of Chicago Press, 2016.
Earlier edition also available in print: Q180.55 M4 B66 2008 (Music Library copy on reserve; ask at the Service Desk)
Sampsel, Laurie. Music Research: A Handbook. 3rd ed. New York: Oxford University Press, 2019. See especially Appendix D: "Chicago Style at Your Fingertips." ML113 S28 2020 (on reserve at the Service Desk)