To be read and reread:
I. Newton, `Scholium to Definition VIII’ (reprinted in full in Barbour, pp.623-28, and in Alexander’s edition of the Leibniz-Clarke Correspondence, pp.152-160).
Alexander, H. (ed.), The Leibniz-Clarke Correspondence, New York, 1956.
You should dip into other writings of Leibniz:
Theodicy, (1710), trans. Huggard, Open Court: 1985.
New Essays on Human Understanding, (1704; first published 1765), trans. Remnant and Bennett, (abridged edition), Cambridge: 1982.
Philosophical Essays, trans. Ariew and Garber, Hackett.
Philosophical Writings, trans. Morris and Parkinson, Everyman:1973.
Of his essays the most important (and the ones you should certainly read) are:
“Discourse on Metaphysics”, 1686;
“New System of the Nature and Communication of Substances”, 1695;
“Metaphysical Consequences of the Principle of Reason,”, 1712.
“Mondadology”, 1714;
“Principles of Nature and of Grace”, 1714.
There is a large literature on the Correspondence, and on the philosophy of space and time in the early modern period. Of this the articles you are expected to read are:
Barbour, J. Absolute or Relative Motion?, Cambridge University Press, 1989, Chap.11, especially Sections 11.3, 11.4, 11.5, 11.6,.
Rynasiewicz R., 'By their properties, causes and effects: Newton's Scholium on Time, Place and Motion—I The Text, Studies in History and Philosophy of Science, 26, p. 133 (1995).
Parkinson G, “Philosophy and Logic”, in The Cambridge Companion to Leibniz, ed. N. Jolley.
McRae R., “The Theory of Knowledge”, in The Cambridge Companion to Leibniz, ed. N. Jolley, Cambridge: CUP, 1995.
Recommended texts, which you are not expected to read, but might like to dip into:
E. Vailati, Leibniz and Clarke: A Study of their Correspondence, Oxford: 1997.
N. Rescher, G.W. Leibniz’s Monadology: An Edition for Students.
N. Jolley (ed.), The Cambridge Companion to Leibniz, Cambridge: 1995.
D. Rutherford, Leibniz and the Rational Order of Nature.
B. Mates, The Philosophy of Leibniz: Metaphysics and Language, Oxford: 1986.
H. Ishiguro, Leibniz’s Philosophy of Logic and Language, Cornell: 1972.
R. Adams, Leibniz: Determinist, Theist, Idealist, Oxford: 1994.
P. Edwards, The Encyclopedia of Philosophy, MacMillan: 1967.