The Taxes are different in Ireland than in Spain. Here, a self-employed must pay the 4% of his/her incomings, unlike in Spain, we must pay 20% of our benefits.
However, in Ireland, if your incoming are less of 5.000 €/year, you don't pay anything to the administration. In the other hand, is not necessary to register for VAT if your annual incoming is less of 37.000 €/year (in the case of services, year 2012), this way you don't charge VAT in your invoices. In my case, I won't register to VAT until next year if my income is more than that amount.
The fiscal year is from November 1st to October 31th next year. Until this date, you don't must worried for pay taxes and bureaucracy. Only you must keep the records of your business.
You can have a business name instead of your own name for calling your business for only 20 €(online). You can apply for it in CRO (Companies Registration Office) with a RBN1 form and you will receive a certificate in a week more or less.
Until next post!