Should husband and wife attend the hajj course together, or is it enough for one of us to go?

Ideally both should attend, because every pilgrim is responsible for the validity of their own worship. Hajj and umrah have pillars (rukun) and obligatory acts (wajib) that each person needs to understand. The wife also needs to know the rulings specific to women, such as what to do if her period comes. If work schedules make it difficult, attend together as often as you can, then revise the course material together in the evenings. Also discuss how you will divide roles, for example who handles the documents and who keeps track of the schedule. Learning together builds a sense of being a team, and a couple who understand the rites (manasik) can calmly correct each other while there. See menstruation during umrah or hajj.