Hey that's really good news that he is back to taking his meds and is ready for a fresh start.
I think the fact that you love your husband and want to do the right thing means that you will be a great support to him.

I encourage you to look at the Bipolar forum and reach-out to some of the users there. I think they could give you some insight into how best to deal with your husband's behaviours.
Regarding the drinking, perhaps you could tell him that you do believe he could stop this habit all on his own, but that he doesn't have to make it so hard for himself. Let him know that it's okay to get help from others. Getting help doesn't make us weak. You could even ask him if there are any ways you could help him to break the habit. Just encouraging him to talk about his feelings may help. Sometimes people try to drown the pain they can't express with alcohol.
You may also like to consider going to see a therapist/counsellor yourself; particularly to help you in this early stage of realising your husband has bipolar disorder. A professional may be able to help you talk through some of your concerns and give you reassurance for those moments when you don't how to support your husband.
No diagnosis, lots of opinions, and a bunch of issues that I haven't quite figured out.