North Light, publishers of art books and magazines, is having a short sale (December 26 through December 30) on eBooks, Magazines, etc. The sale announcement page is:
http://www.northlightshop.com/sale-digital-days
North Light publishes books on art technique. They also publish The Artist's Magazine, Watercolor Artist, and other magazines. I have a couple of their collections of magazine back issues on CD. They're all in PDF format, and reasonably high quality. The paper originals are large format magazines, and they look best on larger sized tablets -- although my 7" Android tablet is usable. They look great on the computer monitor, but they don't look very good on my ereader.
Aside from this sale, which looks pretty good, they sell downloads and CD collections on a regular basis -- and they seem to put them on sale randomly. If you're interested, it's worth checking in periodically.