• S. Blundell: Magnetism in Condensed Matter. Good basic introduction.
• A.H. Morrish: The Physical principles of Magnetism. Reprint from 1965. Detailed and good description of the field. Sometimes old notation, but recommended both for introduction and research.
• W. Nolting, A. Ramakanth: Quantum Theory of Magnetism. Comprehensive theoretical introduction into magnetism. Good theory textbook.
• N. Majlis: The Quantum Theory of Magnetism. Textbook for a theoretical condensed matter magnetism course. Sophisticated
   

Chapter 1:

• Book Molecular Nanomagnetism by Gatteschi, Sessoli, Villain, Oxford Academic Books, 2006
• Molecular nanomagnets: Towards molecular spintronics,W. Wernsdorfer, Oxford Academic Books, 2010
• Textbook online: Lanthanide Molecular Magnets (Springer via HEIDI): Introduces the subclass of lanthanide SMMs, with a good overview in chapter 1.
• Summer school lecture by W. Wernsdorfer, a main player on the field
• Online resouces: Tutorial on Molecular Magnetis on the MolMagWeb
• Review by Nicholas F. Chilton, Molecular Magnetism Annual Review of Materials Research, Vol. 52:79-101 (with a focus on q-bits)
• Review by Eugenio Coronado, Molecular magnetism: from chemical design to spin control in molecules, materials and devices, Nature Reviews Materials volume 5, pages 87–104 (2020) (a more chemistry perspective)
• Review by Stephen J. Blundell, Molecular magnets, Contemporary Physics 48 (2007) 275-290

Chapter 2

• P. Fazekas: LECTURE NOTES ON ELECTRON CORRELATION AND MAGNETISM. Very good theory book bridging back magnetism to electron correlations. High level (but also good for experimentalists).
• Daniel I. Khomskii: Basic Aspects of the Quantum Theory of Solids: Order and Elementary Excitations
• D. I. Khomskii, Transition metal compounds, online via HEIDI