I live in an owner occupied two unit home. I live on one floor and rent out the other. Additionally, I operate a personal business. How should I divide property tax, etc?

If the two floors are truly separate from one another but similar in size, then you could consider the rental floor and your residential floor as two separate properties. 

Enter the information in the rental income and expenses section for the rental portion as if it is a property on its own.  The main thing to consider would be to only enter half of the cost of the property for depreciation, enter half of the property taxes, enter half of the mortgage interest, etc. for any items that are paid for the whole building. 

Use the same idea when entering information for your home office that is included as part of your residence portion of the building.