What tax forms does a U.S. company have to submit for foreign affiliates?

Does anyone have basic IRS tax information for U.S. companies with affiliates in other countries who will earn commissions from the sale of non-tangible Internet services?
I Google this and but didn’t find what I needed. If anyone has experience with this, I just want to make sure I’m aware of all tax forms that need to be filed.

See original post by vectro