Supplier: Dateman Books
Website: Webstore - Ebay Store - Etsy Store.
Products: 1/12 scale books and magazines. You can buy books in kit format for £4.50 or, if you're lazy like me, ready made books for £7 or £8.50 each. Some titles cost a little more, like the Rupert Bear annuals which due to licensing and so on are £16 each, but £7 or £8.50 is the norm. The books come in two sizes - large which equates to A4 in 1/12 sale, or small which equates to A5 - and the price for each title is the same regardless. (i.e. the price difference depends on book series not size.)
The first one I bought was Baden-Powell's Scouting for Boys; it's a hardback with printed cover and legible pages. It really is so well made! Then, a couple of years back, Dateman Books were at the Cwmbran miniatures fair at the Stadium and obviously I couldn't resist buying something from their stall. I went with one of the James Bond titles (the first chapter is printed in miniature), which even has a paper jacket.
They also sell a range of miniature newspapers, comics, sheet music and magazines, which are generally £1.50 each. Here are a couple I bought about five years ago.
Post and Packing: £2.50 for first book, subsequent items free, or 75p for first magazine / newspaper and 25p for each subsequent. (Within the UK)