A good starting place is the Tax Estimator provided by TurboTax on its web site. Walking through the process with the Estimator will tell you everything you need to know for the entire process.

First, you start by entering the personal information that is relevant to your situation. Your personal address is very important in determining state and local income taxes. You also have many personal exemption options as well as your filing status (single, married filing jointly or separately, etc.), that will impact the final amount of your income tax computation.