Data Standards
MIDAS Heritage https://historicengland.org.uk/images-books/publications/midas-heritage/
The above maps to/references CIDOC CRM which has been replaced by ISO 21127:2014 http://www.iso.org/iso/catalogue_detail?csnumber=57832
FISH Forum for general info http://fishforum.weebly.com/
Metadata
Overview of metadata http://www.dcc.ac.uk/resources/briefing-papers/standards-watch-papers/what-are-metadata-standards
Dublin Core http://dublincore.org/metadata-basics/
CARARE metadata for heritage assets and digital resources http://carare.eu/dut/Support/CARARE-metadata-schema
Further Data Standards
IFP gives a good overview of the sector http://archaeologydataservice.ac.uk/ifp/
The Museum collections data standard is Spectrum http://www.collectionstrust.org.uk/spectrum
Documenting The Cultural Heritage provides a good overview of European heritage data http://archives.icom.museum/objectid/heritage/intro.html