Anyone out there a tax person or accountant?

Calculating the square footage of space in the home used and then calculating the number of days of the year and trying to clam that amount against your household costs is probably a waste of time on $500. If you kept a log of mileage, that might be helpful, if you made more than just a few trips. If you bought supplies like drafting paper and pencils or software, I'd include those, if the receipts are dated for 2013.

Of course, we don't really know the amount at this time.

I thought he numbers were $400 for taxable, and $600 for 1099.

http://www.irs.gov/publications/p334/ch10.html