I rent out 1 room in my home. When entering utility exp, do I apportion the amt? EG: room is 20% of home sqft, all utilities are $2K. Do I only enter $400 as utility exp?

Yes, you can enter your rental activity this way and then enter only the expenses attributable to the one room.  Some people find this easier.

However you also have the option of letting TurboTax do the calculations for you.

As a landlord you can also deduct the rental portion of utilities, homeowner insurance, and any repairs, cleaning or maintenance to the entire property.  When you answer the questions about the type of rental and the rental situations (click the screen shot attached to view these questions) you will be asked about personal days and rental days based on your answers to the questions.  

TurboTax will calculate the appropriate amount of your expenses based on the number of days rented. If you rented it all year, it will ask for the percentage of the property being used as a rental which can be determined by square feet of the total home prorated against the square feet of the rental rooms only.

You can also deduct in full any expenses that were directly attributable to the rental rooms only. Examples would be the cost of creating a lease, legal fees for the rental rooms, furniture for the room.

Click the image attached to enlarge and view for assistance on the questions that must be answered.