Taxes for USA expats can be complex. The USA is one of less than a handful of countries that tax citizens on worldwide earnings no matter where they live.
If you are employed by a foreign company and stationed overseas for the full year (in qualifying countries) you will pay tax on your earnings where they are earned and have the first $100,800 (in 2015) of earnings excluded from USA income tax. However earning above that level will be taxed where you earn them and by the USA. Learn about the Foreign Earned Income Exclusion on the IRS web site.
The IWantOut and USExpatTaxes SubReddit are forums to search for more information and learn from others. Taxes for Expats is one service many USA expats use and have been happy with.
Like banking, taxes (at for USA citizens) are one of the more difficult issues of an overseas (including nomadic) lifestyle.
Related: Health Insurance Considerations for Digital Nomads – Finding an International Business Bank as a Digital Nomad – Transfer Money Between Currencies Using New Providers Not Banks And Save