For help with what your fees are for a specific transaction this tool should give you an idea:
http://www.gregledet.net/efcm.htmlIf you take Etsy DC payments, the fees are about the same as what Paypal charges, so each item sold will show those fees too when the buyer pays through DC and the tool will still give you an idea of what it costs.
But for income tax purposes, you need to include your total income from sales (item price plus shipping), and then you reduce that amount by deductions allowed by the IRS. It's all done the schedule C with specific deductions on specific lines for sole proprietors--help with that here:
US Sellers: Help for Filing Income Taxes for Your Small Business
http://www.etsy.com/teams/7722/business-topics/discuss/67739691I lump all the Etsy transaction fees and listing fees together, though if I accepted Etsy payments I'd probably list those separately (credit card fees vs venue fees).