“As an independent contractor who already owes the govt. money, what forms do I need to file”----> As an IC, self employer or a sole proprietor, aslong as you have $400 or more of business income over and above your expenses net earnings, I mean, then you need to file a Sch C or a Sch C-EZ. Also if the amount on Sch SE line 4 is $400 or exceeds 4400, then you need to pay SE Tax, self-employment tax which is a tax consisting of Social Security and Medicare taxes primarily for individuals who work for themselves, like yourself. It is similar to the Social Security and Medicare taxes withheld from the pay of most wage earners. The 2010 Tax Relief Act reduced the self-employment tax by 2% for self-employment income earned in calendar year 2011. The self-employment tax rate for self-employment income earned in calendar year 2011 is 13.3% (10.4% for Social Security and 2.9% for Medicare). Also, you need to pay quarterly estimated taxes .If you are filing as a sole proprietor and/or a self-employed individual, you generally have to make estimated tax payments if you expect to owe tax of $1,000 or more when you file your return. However, you do not have to pay estimated tax for the current year if You had no tax liability for the prior year; you were a U.S. citizen or resident for the whole year; your prior tax year covered a 12 month period.
Please for more info., visit the IRS Websites here;
Estimated Taxes Self-Employment Tax (Social Security and Medicare Taxes) http://www.irs.gov/pub/irs-pdf/f1040sc.pdf http://www.irs.gov/pub/irs-pdf/f1040sce.pdf