If you're recently married, add the IRS to the list of recipients of your name and address change information. If you changed your name, start the name-change process with the Social Security Administration. The updated information will flow from Social Security to the IRS, so you will not have to inform them separately. If you try to file your return under your new name, without having changed it with Social Security, the IRS will likely have a number of questions for you, and it may hold up any anticipated refund.
As part of the name-change process, remember to fill out any employer-required paperwork. You may need to change the amount of taxes you have taken out of your pay, and you will want to be sure your employer is paying any taxes on your behalf under the correct name and marital status.