Is this your primary or a second home? I believe they may be treated differently. You can review the Sale of Home publication from the IRS online at http://www.irs.gov/pub/irs-pdf/p523.pdf
This may provide some of the information you're looking for in your question.
Only a tax professional can advise you whether you have to pay Federal or State taxes on the sale of your home.
When interviewing agents, ask them to provide a net sale worksheet with their presentation. This will estimate all the fees and taxes (other than Federal and possibly State) you will pay at closing. Note: this is only an estimate.