I need to know where I can get a good primary source on Galileo Galilei?

Answer 1

Finding a true primary source on Galileo Galilei will be extraordinarily difficult. A true primary source would be a document written by Galileo or a contemporary of Galileo, thus the document would be quite old.

Copies of many documents that Galileo and others wrote are available, but I suspect they are all in Italian or Latin.

You may look for an English version of Sidereus Nuncius, but it is likely to be a difficult read, even in English.

Answer 2

References
* Allan-Olney, Mary. The private Life of Galileo: Compiled primarily from his correspondence and that of his eldest daughter, Sister Maria Celeste, (nun in the Franciscan convent of St. Matthew, in Arcetri), 1870, Boston : Nichols and Noyes. - Google Books
* Biagioli, Mario (1993). Galileo, Courtier: The Practice of Science in the Culture of Absolutism. Chicago: University of Chicago Press.
* Consolmagno, Guy; Schaefer, Marta (1994). Worlds Apart, A Textbook in Planetary Science. Englewood, New Jersey: Prentice-Hall, Inc. ISBN 0-13-964131-9.
* Drake, Stillman (1953). Dialogue Concerning the Two Chief World Systems. Berkeley: University of California Press.
* Drake, Stillman (1957). Discoveries and Opinions of Galileo. New York: Doubleday & Company. ISBN 0-385-09239-3
* Drake, Stillman (1973). "Galileo's Discovery of the Law of Free Fall". Scientific American v. 228, #5, pp. 84-92.
* Drake, Stillman (1978). Galileo At Work. Chicago: University of Chicago Press. ISBN 0-226-16226-5
* Einstein, Albert (1952). Foreword to (Drake, 1953)
* Fantoli, Annibale (2003). Galileo — For Copernicanism and the Church, third English edition. Vatican Observatory Publications. ISBN 88-209-7427-4
* Favaro, Antonio (1847-1922), ed.[2]. Le Opere di Galileo Galilei, Edizione Nazionale, Vol. xvii. (The Works of Galileo Galilei, National Edition, 20 vols.), Florence: Barbera, 1890-1909; reprinted 1929-1939 and 1964–1966. ISBN 88-09-20881-1. from Google Books. Brief overview of "Le Opere" @ Finns Fine Books, [3] and here [4]
* Fillmore, Charles (1931, 17th printing July 2004). Metaphysical Bible Dictionary. Unity Village, Missouri: Unity House. ISBN 0-87159-067-0
* Finocchiaro, Maurice A. (1989). The Galileo Affair: A Documentary History. Berkeley: University of California Press. ISBN 0-520-06662-6
* Gebler, Karl von. Galileo Galilei and the Roman Curia : from authentic sources, London, C.K. Paul & co., 1879; Merrick, N.Y. : Richwood Pub. Co., 1977. - Google Books ISBN 0-915172-11-9
* Geymonat, Ludovico (1965), Galileo Galilei, A biography and inquiry into his philosophy and science, translation of the 1957 Italian edition, with notes and appendix by Stillman Drake, McGraw-Hill.
* Grisar, Hartmann, S.J., Professor of Church history at the University of Innsbruck (1882). Historisch theologische Untersuchungen über die Urtheile Römischen Congegationen im Galileiprocess ( Historico-theological Discussions concerning the Decisions of the Roman Congregations in the case of Galileo), Regensburg: Pustet. - Google Books ISBN 0-7905-6229-4. (LCC # QB36 - microfiche) Reviewed here (1883), pp.211-213
* Hellman, Hal (1988). Great Feuds in Science. Ten of the Liveliest Disputes Ever. New York: Wiley.
* Koestler, Arthur. The Sleepwalkers: A History of Man's Changing Vision of the Universe 1958, Penguin (Non-Classics); Reprint edition (June 5, 1990). ISBN 0-14-019246-8
Langford, Jerome, Galileo, Science and the Church, third edition, St. Augustine's Press, 1998. ISBN 1-890318-25-6
* Lessl, Thomas, "The Galileo Legend". New Oxford Review, 27-33 (June 2000).
* Naylor, Ronald H. (1990). "Galileo's Method of Analysis and Synthesis," Isis, 81: 695-707.
* Newall, Paula (2004). "The Galileo Affair."
* Remmert, Volker R. (2005). Galileo, God, and Mathematics. In: Bergmans, Luc/Koetsier, Teun (eds.): Mathematics and the Divine. A Historical Study, Amsterdam et al., 347-360.
Settle, Thomas B. (1961). "An Experiment in the History of Science". Science, 133:19-23.
* Sobel, Dava. (1999). Galileo's Daughter. ISBN 0-14-028055-3
* Wallace, William A. (1984) Galileo and His Sources: The Heritage of the Collegio Romano in Galileo's Science, (Princeton: Princeton Univ. Pr.), ISBN 0-691-08355-X
* White, Andrew Dickson (1898). A History of the Warfare of Science with Theology in Christendom. New York 1898.
* Wisan, Winifred Lovell (1984). "Galileo and the Process of Scientific Creation," Isis, 75: 269-286.
* Zik Yaakov, "Science and Instruments: The telescope as a scientific instrument at the beginning of the seventeenth century", Perspectives on Science 2001, Vol. 9, 3, 259-284.

Answer 3

References * Allan-Olney, Mary. The private Life of Galileo: Compiled primarily from his correspondence and that of his eldest daughter, Sister Maria Celeste, (nun in the Franciscan convent of St. Matthew, in Arcetri), 1870, Boston : Nichols and Noyes. - Google Books * Biagioli, Mario (1993). Galileo, Courtier: The Practice of Science in the Culture of Absolutism. Chicago: University of Chicago Press. * Consolmagno, Guy; Schaefer, Marta (1994). Worlds Apart, A Textbook in Planetary Science. Englewood, New Jersey: Prentice-Hall, Inc. ISBN 0-13-964131-9. * Drake, Stillman (1953). Dialogue Concerning the Two Chief World Systems. Berkeley: University of California Press. * Drake, Stillman (1957). Discoveries and Opinions of Galileo. New York: Doubleday & Company. ISBN 0-385-09239-3 * Drake, Stillman (1973). "Galileo's Discovery of the Law of Free Fall". Scientific American v. 228, #5, pp. 84-92. * Drake, Stillman (1978). Galileo At Work. Chicago: University of Chicago Press. ISBN 0-226-16226-5 * Einstein, Albert (1952). Foreword to (Drake, 1953) * Fantoli, Annibale (2003). Galileo — For Copernicanism and the Church, third English edition. Vatican Observatory Publications. ISBN 88-209-7427-4 * Favaro, Antonio (1847-1922), ed.[2]. Le Opere di Galileo Galilei, Edizione Nazionale, Vol. xvii. (The Works of Galileo Galilei, National Edition, 20 vols.), Florence: Barbera, 1890-1909; reprinted 1929-1939 and 1964–1966. ISBN 88-09-20881-1. from Google Books. Brief overview of "Le Opere" @ Finns Fine Books, [3] and here [4] * Fillmore, Charles (1931, 17th printing July 2004). Metaphysical Bible Dictionary. Unity Village, Missouri: Unity House. ISBN 0-87159-067-0 * Finocchiaro, Maurice A. (1989). The Galileo Affair: A Documentary History. Berkeley: University of California Press. ISBN 0-520-06662-6 * Gebler, Karl von. Galileo Galilei and the Roman Curia : from authentic sources, London, C.K. Paul & co., 1879; Merrick, N.Y. : Richwood Pub. Co., 1977. - Google Books ISBN 0-915172-11-9 * Geymonat, Ludovico (1965), Galileo Galilei, A biography and inquiry into his philosophy and science, translation of the 1957 Italian edition, with notes and appendix by Stillman Drake, McGraw-Hill. * Grisar, Hartmann, S.J., Professor of Church history at the University of Innsbruck (1882). Historisch theologische Untersuchungen über die Urtheile Römischen Congegationen im Galileiprocess ( Historico-theological Discussions concerning the Decisions of the Roman Congregations in the case of Galileo), Regensburg: Pustet. - Google Books ISBN 0-7905-6229-4. (LCC # QB36 - microfiche) Reviewed here (1883), pp.211-213 * Hellman, Hal (1988). Great Feuds in Science. Ten of the Liveliest Disputes Ever. New York: Wiley. * Koestler, Arthur. The Sleepwalkers: A History of Man's Changing Vision of the Universe 1958, Penguin (Non-Classics); Reprint edition (June 5, 1990). ISBN 0-14-019246-8 Langford, Jerome, Galileo, Science and the Church, third edition, St. Augustine's Press, 1998. ISBN 1-890318-25-6 * Lessl, Thomas, "The Galileo Legend". New Oxford Review, 27-33 (June 2000). * Naylor, Ronald H. (1990). "Galileo's Method of Analysis and Synthesis," Isis, 81: 695-707. * Newall, Paula (2004). "The Galileo Affair." * Remmert, Volker R. (2005). Galileo, God, and Mathematics. In: Bergmans, Luc/Koetsier, Teun (eds.): Mathematics and the Divine. A Historical Study, Amsterdam et al., 347-360. Settle, Thomas B. (1961). "An Experiment in the History of Science". Science, 133:19-23. * Sobel, Dava. (1999). Galileo's Daughter. ISBN 0-14-028055-3 * Wallace, William A. (1984) Galileo and His Sources: The Heritage of the Collegio Romano in Galileo's Science, (Princeton: Princeton Univ. Pr.), ISBN 0-691-08355-X * White, Andrew Dickson (1898). A History of the Warfare of Science with Theology in Christendom. New York 1898. * Wisan, Winifred Lovell (1984). "Galileo and the Process of Scientific Creation," Isis, 75: 269-286. * Zik Yaakov, "Science and Instruments: The telescope as a scientific instrument at the beginning of the seventeenth century", Perspectives on Science 2001, Vol. 9, 3, 259-284.

Answer 4

The primary sources are mostly in the Vatican Library.