If you gain employment with a foreign company in a foreign country, what are the tax laws when you return to the U.S. For instance, Dubai is a tax-free country. Would you have to pay taxes on your income when you returned to the U.S. Is there a time frame that if you go beyond that then your money would not be taxable? Can you wire money from there to a bank in the U.S. in order to pay bills while you're gone? Would that be taxable?

If you are a U.S. citizen or resident, you must report your world wide income. You must file your tax return if your worldwide income exceeds the filing requirement.
Read Your U.S. Tax Return: U.S. Citizen or Resident with Foreign Income