I'm going to be producing a commercial for a local winery to be aired on a national network. Are there any laws regarding the advertising of alcohol that I need to be aware of (disclaimers, etc.?)

Don't know for sure, but used to be you couldn't show anyone DRINKING it. But that was long ago when I worked in television. Maybe someone in the As business will jump in.

Also I think it will depend on where the ad runs. I seem to recall at least at one time you couldn't show someone actually drinking the product on asds in the States but here in Canada and over in Europe I think it's ok.

Check with the network you are going to run the ad on. Laws may not matter as much as their own rules. I just shot a commercial in a bar (not for a bar), and we had to remove every dart board, clock, and bar sign that had a logo on iot, and could not even have alcoholic drinks in the shots.