There are some changes from last year so look at the instruction sheet to get all the latest info so that you won't make any mistakes.

The IRS says:
Use Schedule C (Form 1040) to report income or loss from a business you operated or a Profit or Loss profession you practiced as a sole proprietor. An activity qualifies as a business if your primary purpose for engaging in the activity is for income or profit and you are involved in with continuity and regularity.

For example, a sporadic activity or a hobby does not qualify as a business. To report income from a nonbusiness activity, see the instructions
for Form 1040, line 21, or Form 1040NR, line 21.
Also, use Schedule C to report (a) wages and expenses you had as a statutory employee, and (b) certain income shown on Form 1099-MISC, Miscellaneous Income.

See the Instructions for Recipients (back of Copy B of Form 1099-MISC) for the types of income to report on Schedule C.
Small businesses and statutory employees with expenses of $5,000 or less may be able to file Schedule C-EZ instead of Schedule C. See Schedule C-EZ for details.
You may be subject to state and local taxes and other requirements such as business licenses and fees. Check with your state and local governments for more information.

Click to download a printabable pdf file of the IRS 2008 Schedule C Form

Click to download printable Instructions for the 2008 Schedule C

As always check the facts as with all government info may be subject to change.