Dressmaking Books Online — A list of online books on the subjects of dressmaking, needlework, lacemaking, netting and more. Most of the books are from the early 20th century, a few from the 19th century.
Fabric Glossary — List of fabric terms from Medieval through mid-20th century.
Northern Society of Costume & Textiles — A group in UK that “was founded ... to encourage the study and preservation of costume and textiles.” They sell patterns made from original clothing, including a dress that belonged to Charlotte Bronte.
Textile Reference Manual — Describes the different kinds of textiles and their properties. Also links to articles about textiles.
Threads Magazine — Lots of good articles on sewing, including basics, garment construction, etc.
Weaving, Lace and Related Topics — A site with documents on weaving, lace, etc. Includes the “On-Line Digital Archive of Documents on Weaving and Related Topics” – books, manuscripts, illustrations and more.
Your Wardrobe Unlock’d — Subscription based website. “This website offers resources, help, inspiration and a sense of community for seamstresses and costume makers who have a burning desire to improve their skills. We do this through articles, features and our core Masterclasses, which give you not a standard How to Sew course, but the basic building blocks of really great professional-quality sewing.”