I would suggest letting him get comfortable before anything else. Let him come to you he will it may take time but be patient. I find that I always talk to my rescues even just mindless crap is fine it is the sound of your voice. It is reassuring and will be comforting to him. Don't let him get away with any bad behaviour but you do not want to scare him. It is really time and love that is the greatest healer for these guys. For you it is patience, don't get discouraged it will all be worth it and we are always here for moral support or any questions. Here is a good tip if you feel like yelling at him don't go outside and yell, stamp your feet and then go back in a you will be calmer. As you watch him see what it is that sets off his aggression. This will be helpful for you to avoid these situations. Also once he feels safe and not in harms way this aggression may become less and less on its own but always be watching. Good luck By the way welcome to the pet.ca board
A dog has so many friends because they wag their tails not their tongues.
R.I.P. Buddy 2002-2008 The best Mastiff ever.
Now owned by Clark the Crazy American Bulldog