I am filing for financial aid for college and need to show that I filed takes in 2007. But the thing is that I can't find the paper work showing this. Where can I get a copy?

You can get copy of transcripts from the IRS. It is free.
Read copy of tax return and transcripts Your U.S. Tax Return: The U.S. Income Tax Topics 1 (http://taxipay.blogspot.com/2008/08/us-income-tax-topics-1.html)

If you filed on-line, contact the tax website you used and see if they can produce a printed copy for you.

If you used a tax professional, he/she will have a file copy they can provide you. Expect to pay a small $5-to-$15 handling fee.

Otherise, request the tax transcripts cited by MukatA.