Business & farm

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 tract 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....
<a rel="nofollow" target="_blank" href="http://quickbooks.intuit.com/self-employed">http://quickbooks.intuit.com/self-employed</a>

ABOUT PAYING ESTIMATES
The first year you don't need to pay estimates as long as you pay in (by withholding) as much as your tax was last year.  But if you will have a big income you should send in estimates so you don't owe too much next April on your tax return.

You must make quarterly estimated tax payments for the current tax year if both of the following apply:
- 1. You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits.
 
- 2. You expect your withholding and credits to be less than the smaller of:
    90% of the tax to be shown on your current year’s tax return, or
  100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months.)