Federal Tax Information
All U.S. citizens or resident aliens must report and pay tax on their worldwide income, even if they live abroad.
Federal Tax Information Sheet
IRS Information for U.S. Citizens that live abroad - Link contains basic tax information that Americans overseas need to know and also includes links to more detailed topics such as the foreign earned income exclusion, foreign tax credit, reporting foreign bank accounts, fulbright grants, state taxes, and a myriad of other topics.