The Spinning Wheel Sleuth is a quarterly magazine published in the US which has scholarly but readable articles about early spinning wheels, mainly North American and European. Their website includes sample articles and colour photographs, as well as subscription details.
Mary Knox’s blog nzspinningwheels.wordpress.com includes the full text of of her book on New Zealand spinning wheels, timelines for Peacock and Peggy wheels, some makers’ leaflets, and articles and blog posts on all sorts of (mostly) related topics.
Ashford and Majacraft, whose current models we have not found it necessary to include, each have their own website with detail about their products. Their websites are:
Internet auction sites can also have snippets of information: a search for ‘spinning wheel’ on New Zealand site Trademe may turn up interesting listings. If you don’t live in NZ or Australia, note that you cannot buy or sell on Trademe.
The various Ebay sites (US, UK and Australia) are sometimes worth a look too, as are Craigslist (US) and Kijiji (Canada).
The discussion groups on Ravelry can be invaluable, particularly ‘Working Wheels’, ‘Spinners of New Zealand’ and groups for the various makers.