Non-residents will be taxed on income sourced in Ireland. The standard rates is 20% with some allowances. Irish tax resident landlords need to pay PRSI (4% of income profit) and USC (2-10%)too. There are a number of expenses landlords can claim against their total gains, including management fees, insurance premiums, utilities and other service charges, RTB (Residential Tenancies Board) registration fees, maintenance costs, capital allowances, wear & tear and advertising expenses. RTB registered landlords can claim the interest on mortgage payment against income.
Always consult with a professional tax advisor. Your estate agent may offer letting & property management services, in which case they can provide quotes.
If you are planning to buy a property in Ireland and use if for short-term lets, instead of your primary place of residence, you may need to apply for a change of use, getting planning permission from the local authority. Your estate agent can advise.