Then yes you will probably owe self employment tax on it. Self Employment tax (Scheduled SE) is automatically generated if a person has $400 or more of net profit from self-employment. You pay 15.3% SE tax on 92.35% of your Net Profit greater than $400. The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare. So you get social security credit for it when you retire.
Maybe you have some expenses you can deduct from it.
When you are self employed you are in business for yourself and the person or company that pays you is your customer or client.
To report your self employment income you will fill out schedule C in your personal 1040 tax return and pay SE self employment Tax. You will need to use the Online Self Employed version or any Desktop program but the Desktop Home & Business version will have the most help.
Here is some IRS reading material……
IRS information on Self Employment
http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Self-Employed-Individuals-Tax-Center
Pulication 334, Tax Guide for Small Business
http://www.irs.gov/pub/irs-pdf/p334.pdf
Publication 535 Business Expenses
http://www.irs.gov/pub/irs-pdf/p535.pdf
