Which US Tax forms must my husband and I submit for 2008 while living and working self-employed in Ireland? Is it better to file individually or jointly?:confused: Thank you!

Form 1040 with schedule C or C-EZ (Form 1040) for self employed income. Yourself employed income is subject to SE tax at 15.3%.
Then you will claim foreign tax credit or use foreign income exclusion form 2555. Read: Your U.S. Tax Return: U.S. Citizen or Resident with Foreign Income (http://taxipay.blogspot.com/2008/03/us-citizen-or-resident-with-foreign.html)

Assuming you are both either US citizens or green card holders, and assuming this is one business you are enjoying together, you will file a Form 1040.
Additionally you will file a Sch C to report the net profit of this company unless it is an Irish corporation or partnership, in which case get professional help.
You may each exclude 87,600 from income by using Form 2555.
If you have kids 17 or under use Form 1116 (foreign tax credit) instead of the exclusion if your Irish tax is the same or more than your US tax.
Why would you wish to file separately?