National Museums of Scotland
Comprises various national Scottish museums and collections, now answerable to the Scottish Executive. Site provides news and information on the museums, collections and events.
http://www.nms.ac.uk

National Portrait Gallery
Provides details of the permanent collection, searchable by artist, subject or medium, as well as details of temporary exhibitions and events, visitors information, membership and online shop.
http://www.npg.org.uk

Tate
Includes information on the Tate Britain and Tate Modern galleries, including details of the collections, exhibitions and events and interactive floorplans. Also includes online shop and membership details
http://www.tate.org.uk

The National Galleries of Scotland
Comprised of the National Gallery of Scotland, the Scottish National Gallery of Modern Art, the Dean Gallery and the Scottish National Portrait Gallery.
http://www.natgalscot.ac.uk

The National Gallery
Collection of around 2300 Western European paintings from 1250 to 1900. Provides details of the permanent collection, its artists and temporary exhibitions, as well information on the gallery and its facilities.
http://www.nationalgallery.org.uk

The National Gallery Shop
Books, posters and other gifts inspired by paintings in the collection.
http://www.nationalgallery.co.uk