I graduated college in May, 2010 and have accepted a paid intership through December 31, 2010. I am getting paychecks every two weeks for the amount of hours worked with no taxes being withheld. What taxes am I liable for?

FICA, Medicare for starters... no free ride on those, depending on where you live you may have local wage taxes, State income tax, and Federal income tax.

You are being paid as an independent contractor, which means you have to file Schedule C and SE (with Form 1040) to report that income.

The GOOD NEWS is you can deduct a lot of your expenses associated with working on the internship.

The BAD NEWS is that, inaddition ot federal and state INCOME taxes, you will owe SELF-EMPLOYMENT TAX at a 15.3% rate of the net income from the Schedule C.

QUOTE," paid internship no taxes being withheld from paychecks. What taxes am I liable for?"---Just for reference, if you are claimed as a dependent by your parents, then the incoem is reported asother income on your tax rerturn. And you will have a tax liability on the excess of your income over your standard deduction.
But if not, then you are being treated as an independent contractor as explained above.