Foreign Tax paid - how to report and get a credit or deduction?

I received a 1099-Div showing that a dividend I received last year had a foreign tax paid (to Ireland).  I am confused about how to report this.  There's a dialog box asking me to specify if this is US Source Income, Foreign Source income, or just the more general Beneficiary level.  I have communicated with the company involved (Seagate, which is a US company, so far as I know), and they are not being helpful with this.  What to do?  

Second question... how do I know whether to take the tax paid as a credit or a deduction?

Thanks,

Andy