Arts & Music

Antiques

Bonham's & Butterfields: Local appraisals.

Architecture

The Great Buildings Collection:History,timelines,3D walkthroughs, free model design.

Fashion

Fashion Era:Fashion history, clothing design templates, resources.

Fine Art

Artcyclopedia: Fine art spanning eras and movements,biographical and visual material.
Art Lexicon: Definitions, acronyms.
Bridgeman Art Library: Fine art resources,images from over eight thousand collections.

Worldwide Museum directoryDirectory of on-line museums and museum-related resources.

Crafts

Craftster: Collaborative site with instructions for hundreds of projects.

Instructables:"World's Largest Show-n-Tell".

Museums

Shoe Museum: Online virtual museum.

Music

Radio

Sheet Music: Most free, some for sale.
Sheet Music Archive: Classical music. 2 free downloads per day.