Books by Jacques Maritain:

Oeuvres complètes de Jacques et Raissa Maritain in 15 volumes. Editions Universitares Fribourg, Suisse, éditions Saint-Paul, Paris. The volumes are presented in chronological order. Notre Dame Press is publishing various volumes in English. Older English editions include:

_____ (1930) An Introduction to Philosophy. Translated by E.I. Watkin, Sheed & Ward, NY.
_____ (1940) Science and Wisdom. NY: Charles Scribner's Sons.
_____ (1952) "On Knowledge Through Connaturality" in The Range of Reason. NY: Charles Scribner's Sons.
_____ (1952) "The Immanent Dialectic of the First Act of Freedom" in The Range of Reason. NY: Charles Scribner's Sons.
_____ (1953). Creative Intuition in Art and Poetry. New York: Meridian Books, The World Publishing Co.
_____ (1954) Approaches to God. Harper: NY.
_____ (1955) An Essay on Christian Philosophy. NY: Philosophical Library.
_____ (1956) Existence and the Existent. NY: Image Books. (Deep metaphysics.)
_____ (1959) The Degrees of Knowledge. New York: Charles Scribner's Sons. (Maritain's map of how to integrate the sciences, philosophy, theology and mysticism.)
_____ (1962) A Preface to Metaphysics. New York: Mentor Omega Books. (More deep metaphysics.)
_____ (1968) The Peasant of the Garonne. New York: Holt, Rinehart and Winston.
_____ (1973) Approches sans entraves. Ouvrage publié par le Cercle d'études Jacques et Raïssa Maritain. Fayard. (English translation by Notre Dame Press.)

Maritain, Raissa. (1961) Adventures in Grace, and We Have Been Friends Together. Garden City, NY: Image Books.

Kernan, Julie. (1975) Our Friend, Jacques Maritain. Garden City, NY: Doubleday & Co. (A good basic biography on the Maritains.)

Aquinas, St. Thomas. (1949) On Being and Essence. Toronto, Canada: The Pontifical Institute of Mediaeval Studies.  
_____(1972). An Aquinas Reader. Edited, with an introduction by Mary T. Clark. A Doubleday Image Book: NY. (A good selection of deep philosophical texts to ponder.)

Bañez, Dominic. (1966) The Primacy of Existence in Thomas Aquinas. Chicago: Henry Regnery Company. (Bañez was one of those Thomist metaphysicians who understood the primacy of the act of existence.)

Carlo, William E. (1966). The Ultimate Reducibility of Essence to Existence in Existential Metaphysics. Martinus Nijhoff: The Hague.

de Finance, Joseph. (1945) Etre et Agir. Paris: Beauchesne et ses fils, éditeurs. (One of the book that inaugurated a renaissance of existential Thomism.)

Gilson, Etienne. (1937) The Unity of Philosophical Experience. Charles Scribner’s Sons: NY.
_____ (1949) Being and Some Philosophers. Toronto, Canada: Pontifical Institute of Mediaeval Studies.

Johann, Robert. (1966) The Meaning of Love: An Essay Towards the Metaphysics of Intersubjectivity. Paulist Press.

John, Helen James. The Thomist Spectrum. NY: Fordham University Press, 1958. (On the different schools of Thomism.)