If you are looking for specific information relating to your family history research, for example, old newspaper records, the following organisations and websites may be useful.
Linen Hall Library - contains several genealogical resources, including an index to births, marriages and deaths for 1738 to 1864 from the Belfast News Letter.
Libraries NI - this website contains links to Ancestry Library Edition, an online database which contains census collections, shipping lists, immigration records and maps.
National Archives UK - access to more than 11 million historical government and public records, including military records, passenger lists for UK ships and local and national maps.