G.♣.
My husband has been in recovery for over 20 years, so for at least 10 years when I met him. He attends 2 meetings each week. He also sponsors a couple of guys and mentors several. Probably the biggest thing I do (besides never have alcohol in the house) is treat his meetings as sacred (only ask him to miss if absolutely necessary) and be hospitable when "the guys" come over (which is just about every weekend).
ETA - I just asked my husband if there was anything I did to support him, and he said letting him do what he needs to do (meetings, AA gatherings, etc). When I told him why I asked, he said, "Tell her she needs Alanon." If recovery is new to him, you really do need Alanon. You will need support, too. You will need to be able to talk to other people who have been there. You might even want to get a sponsor.