Ceredigion Archives have a link to an useful copyright guide compiled by Tim Padfield
The National Library of Wales. The major repository of information relevant to Welsh genealogy, such as Bishop's Transcripts, Parish Registers, Marriage Bonds and Allegations, Nonconformist Records, Probate Records, Tithe Maps and Apportionment Schedules, Legal and Administrative Records, Estate Records and Personal Papers, Pedigree Books, Newspapers, etc.
Here is a Contents listing of NLW journals, with links to extracts from these on Genuki
The National Archives (TNA). Formed by a merger of the Public Record Office and the Royal Commission on Historical Manuscripts, is a major repository for English and Welsh records.
Archives Network Wales an online catalogue of the collections of the main archive repositories in Wales
The National Archives has details of many archive repositories in the UK with links to their web sites, if any.
Manorial Documents Register on the National Archives site
People's Collection Wales - " provide services and a website for you to share your memories of Wales in photographs, sound recordings, documents, videos and stories. Celebrate the history of: your community; your family; villages, towns and cities; industries; and traditions
Copac is a union catalogue "Search c.90 UK and Irish academic, national & specialist library catalogues"
Archives Hub. - "Use the Archives Hub to find unique sources for your research. Search across descriptions of archives from over 1,000 years of history, held at over 300 institutions across the UK."
The Royal Commission on the Ancient & Historical Monuments of Wales (RCAHMW) "The Royal Commission on the Ancient and Historical Monuments of Wales has a leading national role in developing and promoting understanding of the archaeological, built and maritime heritage of Wales, as the originator, curator and supplier of authoritative information for individual, corporate and governmental decision makers, researchers, and the general public. ...It holds a unique collection of photographs, maps, images, publications and reports within its archive, The National Monuments Record of Wales, which can be consulted on our online database Coflein
British Library A very comprehensive online catalogue.
National Museums & Galleries of Wales
ARCHAEOLEG CAMBRIA ARCHAEOLOGY (Dyfed Archaeological Trust). One of the four Welsh Archaeological Trusts working to help protect, record and interpret all aspects of the historic landscape. The other 3 are; Gwynedd Archaeological Trust, Clwyd-Powys Archaeological Trust, Glamorgan-Gwent Archaeological Trust.
Bangor University Library - includes an Archives and Welsh Library section
University Research Centre, Lampeter - includes the Founders' Library