There is just a ton of free information on the web on training issues. Thor is showing aggression - he believes he's the boss. I suspect he is. or source is:
http://www.flyingdogpress.com/ This author is very good! Try also
http://www.petplace.com/
and
http://www.yourpurebredpuppy.com/
I think Thor needs some training. You could also talk to a local trainer and see if you can buy an hour's worth of his/her time for a prvate session and discuss the issues that are the worst. Mine charges $35.00. Good luck!!