http://www.nationalarchives.gov.uk/help-with-your-research/
The official archive and publisher for the UK Government, and for England and Wales. The National Archives is home to millions of historical documents, known as records, which were created and collected by UK central government departments and major courts of law.
Some records are available online, others are available through partnerships with Ancestry and Findmypast.
There are also some useful tutorials, podcasts and videos on translating Latin and palaeography, for example. (Palaeography is the study of old handwriting.)