Deep Learning: An MIT Press Book in Preparation
Add to reading list in iOS works well for this sort of thing as it caches offline.  I tried converting this sort of thing to PDF so I could read it on my kindle, but I found that my 6 inch kindle was terrible for this sort of thing.  Also, the amazon conversion process couldn't handle images very well.There really is, I think, a market for a large form factor e-reader for reading stuff offline.  Nice and distraction free, long battery life, etc.