Reshet Oholei Yosef Yitzchak Lubavitch, named for the Previous Rebbe, is the network of Chabad schools in Eretz Yisrael. The Rebbe's letters to its administration in the Igros Kodesh span roughly 5712–5723 (1952–1963). See also the page for Rabbi Yitzchak Ginzburg, one of its administrators.
Expanding pure Jewish education. The Rebbe urged the network's leaders to dedicate themselves wholeheartedly to expanding Jewish education through Oholei Yosef Yitzchak (IK 2538), and to widen their efforts in education generally (IK 6924). He taught that education continues beyond graduation, keeping students connected to Torah (IK 6338).
Administration. The letters guide prudent management at the start of new projects (IK 1608), upholding institutional standards (IK 1721), managing from afar amid changing circumstances (IK 1790), honest self-evaluation in leadership (IK 2095), handling deficits and financial challenges with careful planning and unity (IK 2153, 2790), navigating institutional changes and disputes with priority on peace and mission (IK 2302), and how to respond to new institutions seeking to join the network (IK 7992). With proper order and dedication, the Rebbe wrote, leaders receive all the strength they need from Above (IK 5889).
The school year and special times. The Rebbe asked the schools to extend learning beyond the official calendar and begin early in Elul (IK 3717), to hold special Tishrei programs for students and their families (IK 4716), to use Kislev and Chanukah as opportunities (IK 8256), to plan early for the new year with unity among staff (IK 7978), and to run summer camps even when starting late (IK 4605). During Shemitah, he supported centralized delivery of produce to distant schools (IK 6629). On teaching positions for avrechim, see IK 5593.
Sources: the Rebbe's letters cited above.