John Ferrar's Directory of Limerick (1769), partly online at www.celticcousins.net, was the first directory to deal specifically with a provincial town, and the practice spread throughout Munster in the remaining decades of the eighteenth century, with Cork particularly well covered. In the nineteenth century, local directories were produced in abundance, especially in areas with a strong commercial identity, such as Belfast, the north-east and, again, Munster. The quality and coverage of these varies widely, from the street-by-street listings in Martin's 1839 Belfast Directory to the barest of commercial lists. The best online collections are for the city and county of Cork at Cork City Library's site, www.corkpastandpresent.ie, and for Belfast and Ulster generally at PRONI, nidirect.gov.uk/proni.
Carty, James, Bibliography of Irish history, 1870-1911, Dublin: nli, 1940. nli rr,
Evans, Edward, Historical and Bibliographical Account of Almanacks, Directories etc., in Ireland from the Sixteenth Century, Dublin: 1897. nli Ir 9410016 e 3. 149 p. Reprinted Blackrock, Co. Dublin: Carraig Books, 1976.
Keen, M.E.,A Bibliography of Trade Directories of the British Isles in the Victoria and Albert Museum London: Victoria and Albert Museum, 1979. nli G 01742 v 1. 121 p.
In addition, ArchiveCDbooks went about uncovering forgotten local directories in the
copyright library of Trinity College, Dublin, and republishing them. Their
website, www.archivecdbooks.ie, now appears to be out of use, but most if not all of their products appear to be available at the Irish Family History Centre website.
The best guide to which directories are online (and whether they are free to search) is Shane Wilson's database guide at swilson.info.