Hey there,
Sounds like your dog is just reacting badly to the move and upheaval of his known life and environment - makes more sense if he was a bit nervous to begin with. You said you moved last month, which is only a bit of time in the new location - so I think this behaviour will naturally tone down the longer you are in your new home and your dog gets more and more used to it. He may be "protecting" your house as his new territory, and may be thinking along the lines of it being necessary, otherwise he'll get moved again.
To help calm him down when people come to the house I would strongly suggest using the time out method. We've advised quite a few members about it and it seems to improve unwanted behaviour. It is what it says, basically - when someone comes to the door and your dog goes berserk, or anytime he starts barking at anything - immediately get him by the collar or a hold of him somehow, and put him in a quiet, dark room by himself to calm down. Leave him in there at least 10 minutes or so, or until he's totally quiet and calm. Let him out saying "good boy". As soon as he does the unwanted behaviour again, he immediately goes back into time out. The key to this is getting him IMMEDIATELY, and putting him in time out EVERY TIME he misbehaves. Most dogs catch on that acting a certain way means they will be shut up by themselves, and most dogs don't enjoy that. It worked really well for my own dog and his barking at our front gate.
Try not to let him "patrol" the front of the house (or wherever is facing your gate/wherever people walk past and set him off barking) - especially not alone. Try to leave him home alone either in the back yard on an exercise lead or in his kennel, or in the house but shut out of the front of the house area. You need to discourage his ability to watch who is passing by and reacting to them, so limit his access to these areas where he will become territorial. He should never be there on his own, and when you're with him, try to either distract him before people are in front of your house (you'll have to pay attention to who is approaching!) or use the time out method here too.
I hope this makes sense, and I really hope it helps. You could also look into a DAP pheromone spray or plug in for the house - it excretes natural dog pheromones that help some dogs calm down and relax in the environment - your vet can tell you more if you're interested.
Other members I'm sure will have aweseome advice too, please keep us updated on how things go and if you're seeing any improvement!