Hi, have a good look through :-
Guidance - Students (INF 5)
You will see there is a section entitled "Can I work" that answers your specific question. So you do not need a Work Permit as such but your work hours are limited to 20 hours per week during term time. What INF 5 does not make totally clear is that is that outside of term time you can still work but your hours are not limited to 20 per week.
Can your husband work? Answered by the section "Will my husband or wife be allowed to work?".
Nursing? Indeed a good choice ... in the sense that there is a great shortage of nurses in the UK ... and therefore you would not find it difficult to find permanent work in the UK after you have qualified.
But the way, where are you and your husband from?