break in (a) new employee

Translations
вводить (нового сотрудника) в курс дела
We need to break in a new employee before the busy season starts.
Нам нужно ввести нового сотрудника в курс дела до начала напряженного сезона.
Definitions
To help a new employee become familiar with their job duties, workplace procedures, and company culture, often through training and guidance during their initial period at the job.