(UK) Last time I started in a unioned job the company (voluntarily?) told me about it during my induction, there were flyers in the break room, a poster in the break room with a named representative on my floor (a regular worker like me, it was voluntary) and official rep who I could call. Maybe once or twice a year the union did a presentation in a meeting room at the office and you could could take the hour (unpaid) to go and watch, after which you were encouraged to sign up. Semi regular emails through the year to my company email address about pay and bonus negotiation etc.
(UK) Last time I started in a unioned job the company (voluntarily?) told me about it during my induction, there were flyers in the break room, a poster in the break room with a named representative on my floor (a regular worker like me, it was voluntary) and official rep who I could call. Maybe once or twice a year the union did a presentation in a meeting room at the office and you could could take the hour (unpaid) to go and watch, after which you were encouraged to sign up. Semi regular emails through the year to my company email address about pay and bonus negotiation etc.