It is not an expense.
create an asset account and book the costs to that asset account, create a sub account for accumulated depreciation.
It is what the IRS calls a section 197 intangible, and it is depreciated over 15 years. There are exceptions (there always are with the IRS) if this purchase of a trademark is associated with the purchase of a franchise.
Item 11
http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Intangibles