I have been offered a package of $25000 per annum.Please help me know how the taxes are deducted.About different types of taxes & the % of each tax deducted from the salary.I get pay cheque twice a month i.e. on 15th & 30th of the month.
My wife is on an F1 visa & I am on H1b.She works as assistant with her professor in the university where she is studying & works of 13 hr a week.She gets around $ 400-450 per month.Please let me know if you need any further information.
Thank you.

Your combined income will be $30,100 ($25K for you and $6,100 for your wife).

You will pay Social Security (6.2%) and Medicare (1.45%) at the percentage noted on your $25,000 annual income; that's $1,550 for Social Security and $363 for Medicare. Your wife's income is exempt from FICA taxes.

Assuming that, in 2009, you will file jointly with your wife, the first $18,300 (your and her personal exemption of $3,600 times 2 plus the joint standard deduction of $11,100) of your combined $30,100 income will be exempt from taxes, so your taxable income is $11,800.

Expect an annual federal tax liability of about $1,200.

You did not identify the state where you are located, so I cannot comment on the state income tax.