I received a fair sum from overseas, it was not a gift, but it was not from employment either, more like providing information and being paid for it, do I need to report it in my tax return

If you are a U.S. citizen or resident, then you must report your worldwide income.
Since it is not gift, wages, interest or dividend income or capital gain, then it self employed income. Self employed income is reported on schedule C (Form 1040) and it also subject to SE tax at 15.3% (even if it is not a U.S. source income).
Read: Your U.S. Tax Return: U.S. Citizen or Resident with Foreign Income

If it is a gift or inheritance, then you don't have to pay any U.S. tax but you will file Form 3520 is the amount exceeds $100,000.

If at any time during the year you had more than $10,000 in foreign accounts, then you must file form TD F 90-22.1. It is mandatory.
Read Foreign bank and financial accounts