Note: this is not the well-known kabbalist Rabbi Yitzchak Ginsburgh (born 1944), who came to Eretz Yisrael only in 1965. These letters (about 5717–5724, 1957–1964) are addressed to an administrator of the Chabad school network in Eretz Yisrael. I did not find a reliable published biography of him; the summary below is drawn from the letters themselves.
Running the school network. Rabbi Yitzchak Ginzburg held a central administrative role in Reshet Oholei Yosef Yitzchak Lubavitch, the Chabad education network in Eretz Yisrael, including its secretarial work. The Rebbe guided him on strengthening the schools and their administration with enthusiasm and careful financial oversight (IK 5884), teacher training and exam results (IK 8085), school registration and summer planning (IK 8055), and running the network by accepted best practice, seeking broad support without political entanglement (IK 8061). He urged full dedication to this holy work rather than dividing his focus (IK 8042), and to report difficulties promptly rather than let them grow (IK 8056).
Unity among staff. The Rebbe stressed patience and unity in handling disagreements with teachers, retaining loyal staff, and strengthening the unity of the network (IK 8087, 8116), and focusing Chabad's efforts where they are most needed rather than duplicating existing institutions, as with teacher seminaries (IK 8145).
Youth work and summer camps. He described youth work as a privilege and a channel of blessing (IK 6064), advised on naming the summer camps and on how openly to publicize their Chabad affiliation (IK 6317), and asked for careful camp planning that would not disrupt the schools, with clear financial responsibility (IK 8211).
Communal events. The letters also cover organizing Chanukah seminars (IK 8073), preparing for Yud-Beis Tammuz and Yud Shevat gatherings (IK 8100, 8750), matzah baking in Kfar Chabad (IK 8391), and the Hakhel campaign in Tishrei (IK 9227). The Rebbe encouraged him to approach each new school year with a "lechatchilah ariber" attitude (IK 6992), and to take joy when even former opponents came to recognize the work (IK 8212).
Sources: the Rebbe's letters cited above.