The Rebbe's guidance on secular studies, college and learning a trade for young people — and for parents deciding for their children:
Young years are for Torah. Time in one's youth is far more precious than later — what is planted then grows like a tree rather than a single crop (IK 1921, 3213). A boy of fifteen should not leave yeshiva to learn a trade, and at thirteen or fourteen Torah study must stay central (IK 2025, 3556). Don't take a son out of yeshiva for financial reasons (IK 3614). A son of eighteen should study calmly and not be troubled by thoughts about how he will earn a living; the One who sustains everyone has already prepared his livelihood (IK 3302). A matriculation certificate is not the only way to secure a child's future (IK 7307). Where possible, give several years exclusively to Torah study without mixing in secular subjects (IK 6276, 7006).
Children's secular studies. Limiting secular studies and adding Torah strengthens children spiritually and physically (IK 2268). This is each parent's own responsibility for his children, not something to leave to the school's policy (IK 5825). A yeshiva should not change its program to add general studies (IK 3638). See also the Tanya's and Rambam's views on secular wisdom (IK 495).
College. The Rebbe strongly discouraged college for young men from chassidic homes (IK 729). College takes a large part of one's limited time, fills some of it with things that contradict one's mission, and sets an example others will follow (IK 755). For a son with fine qualities, college was not advisable while its atmosphere remained as it was (IK 10377). Torah learning should not be cut back for the sake of college studies (IK 9029).
Weighing each case. If a course of study is nearly done, doesn't conflict with yiras Shamayim and is the parent's wish, it is worth completing; if much time is still needed, weigh the gain against the loss (IK 1921). A young man already studying may finish his certificate while setting fixed daily times for Torah (IK 10871). For a struggling daughter, the Rebbe recommended she continue her studies at Stern College (IK 10944), and a girl studying secular subjects must continue Jewish studies too (IK 9808). A son who is struggling in yeshiva may do vocational training together with Torah study, ideally close to home (IK 9152). Not every young man's portion is full-time learning; the path of Zevulun — supporting Torah and setting fixed times for learning — is also a path (IK 8200). When choosing a profession for a son in uncertain circumstances, prefer one with shorter preparation (IK 10153). Be patient about further degrees (IK 8531).
See also: Livelihood – Choosing a career or job; Livelihood – Torah study vs. going to work; Parenting – Choosing a school or yeshiva for your child.