Here is a collection of links I have found useful when I have been gathering research for various projects, I hope you find them useful too!
FAVOURITES
Phiala's String Page - so much more exciting than it sounds! Tablet weaving, sprang, lucet, naalbinding... all sorts of archaic crafts!
La Couturiere Parisienne - historical costume
CELTIC
Mogh Roith -Living History and Experimental Archaeology Group based in Counties Clare and Limerick
Echna's Celtic Re-Enactments Page - sections on clothing and crafts - 5th C
A (much) Smaller Social History of Ancient Ireland - includes sections on historical costume
GENERAL
Demode - historical costume The Costumers' Manifesto - lots of links