Over the years I've been selling vintage I've learnt a lot, though I started out with just what they call 'they eye' . I have always enjoyed study so have equiped myself with a group of good books to turn for help when I'm particuarly stumped on a fabric or piece of lace or whatever.
Here is a quick list of some of those books. If you can get your hands on a copy you too will find them invaluable.
Fabrics by Ann Ladbury copyright 1979 & 1985 Sidgwick and Jackson London. This is probably the best reference book I have. It names and describes the fabric then goes onto uses and care with special notes.
Textile Designs two years of European and American patterns organised by motif, style, colour, layout and period. Susan Meller & Joost Elffers. 1991. Harry N Abrams, Inc. Next best book with 1823 colour photos/illustrations of fabric, its just divine to look at and helps you name that look.
Twentieth Century Pattern Design textile and Wallpaper pioneers by Lesley Jackson. 2002. Princeton Architectural Press. This books is in one word Amazing! you will learn so much about fabric and design history here with great photos, every major and some minor movements and designers are covered.
Textiles 2 editions by Norma Hollen, Jane Saddler, Anna L Langford. 1968 & 1979. The Machmillan Company /Collier - Machmillan Limited, London. These text books are fabulous if you want to get deeper into textiles and the manufacturing processes used, these really have loads of technical info.
Textiles for Modern Living by E P G Gohl & L D Vilensky. 1971. Cheschire Publishing Pty Ltd Melbourne. Another school text book with lots of detailed production info but a little more readable than the others.
You really will learn lots from all these books. The textbooks you might find in opshops/thrift stores the the others on amazon.