Agressive behaviors...advice please!

When he growled I would tell him "no growl" and hold his muzzle shut. My husband would yell "bad dog" and smack his snout (which BTW I hated because he obviously isn't learning from it so why keep doing it??

 
I would definitely discontinue either of these tactics.  The last thing you want to instill is that bad things happen with that "other" dog comes around.  I have two dogs, labs, who've had some aggression issues and the very best advice I can give you is using NILIF program.  If you're not familiar with it, you can google it and find lots of info.  You also might want to read up on resource guarding and aggression.  There's some great articles at this link:
[linkhttp://www.flyingdogpress.com/artlibreg.htm]http://www.flyingdogpress.com/artlibreg.htm[/link]
 
I think you'll find that if you can establish yourself as the leader, then your dog will feel less likely to think he's the leader and needs to control the show.  Until then, I'd keep all things such as toys, treats, etc., put away when there are other dogs around.

Yes, any kind of violence will help, yelling wont  help either
 
Actually YOU should be the "dominant" one, not your dog, you have the be the "leader" of your pack and you can decide if you want to have a hierarchy or not (i rather not since then they wont be fighting for 2nd place)

Cesar Millan says:

"Bringing Home a Newly Adopted Dog
In my work, I get to meet the most wonderful people and I try not to be too hard on them when they are my clients, but usually I#%92m telling them exactly what they don#%92t want to hear – that they are usually the reason for their dog#%92s problems and they need to change the way they relate to their dogs for their own good.
It is hard to resist wanting to spoil a new pet, especially if you have just adopted a homeless animal. Owners will bring their new friend home, constantly hug the dog, stroke the dog, bring the dog to bed with them, and tell it, “It#%92s all right. You#%92re safe now.”
The problem is the dog doesn#%92t feel safe at all. It will sense it is with a person who doesn#%92t have a “plan,” knowing that they are not with an assertive leader. One of two things will happen: The dog will develop an issue stemming from that insecurity –or existing issues will get worse–or the dog will immediately take the leadership position so that at least someone is in charge! Remember that the majority of shelter dogs are already stressed and nervous or afraid and can become aggressive if they don#%92t feel they have that strong, calm-assertive leader at their sides.
In the wild, when a new dog joins an existing pack, they already have a position for it. It will either be a leader or follower. The new dog knows what#%92s expected of him, and what to expect. Most people don#%92t have such a plan, and when a dog finds himself in front of owners who do not assert themselves correctly, the dog is going to create the plan for them.
The right way to bring a rescued dog into your home involves understanding the leadership role. The first thing you must do upon leaving the kennel or shelter is to take the dog for a walk. This will rid him of some of his anxious energy. Resist the urge to coddle it. Affection must come later, when the leadership role is fully established. And don#%92t worry that you are hurting the dog#%92s feelings by withholding affection. You are not. The most important thing it needs to know is where it belongs in the new pack."