Sole proprietor would be self employment income unless you set up a Single Member LLC as a S corp or a corporation or partnership.
Some general info on self employment...........
You will need to keep good records. You may get a 1099Misc at the end of the year if someone pays you more than $600 but you need to report all your income no matter how small. You might want to use Quicken or QuickBooks to keep track of your income and expenses.
There is also QuickBooks Self Employment bundle you can check out which includes one Turbo Tax Online Self Employed return....
http://quickbooks.intuit.com/self-employed
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
