Income tax benefits of different brackets?

If you file jointly you owe less in tax per dollar earned. Now sometimes there is still a benefit to file separately, it usually comes when the couple has pay that is not very different (for example one earns 80K and one earns 50K) and one of the two has a lot of medical expenses (equivalent to at least 10% of income so the deduction, which doesn't start until 7.5% of income, kicks in). Really though the circumstancs are pretty rare, if there is anything unique about your stuation it might come into play but if you are typical, i.e., both working, nobody has any strange deductions, nobody has children from prior marriages etc) you want to file jointly.

Your question is too broad. But, to help you out, go to this link:

http://www.irs.gov/localcontacts/index.html

The Tax Rate Schedules are shown in the link so you can see the tax rate that applies

to all levels of taxable income. Do not use them to figure your tax. Instead,

see the instructions for line 44 that begin on page 37.

It is huge pack could not be place here,

If you are married you must file MFJ or MFS you canno't file single unfortunatly

it isn't a matter of benefits, it is a matter of how you are legally required to file