There are many good tips in this thread. Do your work and not fear or show fear. You will find bullies everywhere. 
I want to add:
You will not be the only person being bullied by him. Support others if they get bullied by him. Get get contact with other people.
Create in secret an event log with facts also including your actions to try to stop the bully that you can present later if nothing else helps. (Perhaps also create a private diary with the more emotional aspects that you do not want to present to everyone).
People react different in a group than in a 1 to 1 conversation. Do not fear to talk 1 to 1 with him if he crosses your boarders.
Try to see why the bully is behaving this way. He is the person who can the biggest problems as he can even get fired because of this (also if he is your boss!). This can even make him more insecure or aggressive.
If it is a complete company structure based on fear and/or if he also is [and will stay] the [only] owner of the company you should decide if you like to continue to give your time and energy to this company in exchange for some money.)