If you are researching Ancestors in Northen Ireland then i would recomend the web site Emerald Ancestors. This site covers Irish Ancestors in Counties Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone. It is a paid site but at 10 pounds for one month,i think its good value. If you have a friend researching the same area then it pays to take the monthly membership in turn. It is very easy to do look ups for each other. The main information on the site covers marriage and birth records.