Below is a humorous video showing a mediaeval monk learning how to use one of the new-fangled codex books, rather than a simple one-sheet scroll. It's a popular skit from a Norwegian TV show which has since become a YouTube hit. (The changeover from one-sheet scrolls to bound book-style codices took place well before the Mediaeval Era, but don't let that spoil your enjoyment; it's the only item I've seen addressing the impact this new "invention" - the hand-written book - must surely have had.)
I'm posting it as I've been holding off on the usual kind of post, which usually takes the best part of my weekly day off to compile and check, until the hosting situation with Google's Blogger is clarified. (There have been rumours Google is "moving on" from Blogger, and that it will shortly go the way of so many other free setups. Google has sent out a warning to all account holders to back up their posts, so I'm busy doing this as well as looking out for another possible ad-free online home, after 5 years here. )
In the meantime, if you want to see or own a real old-style codex for yourself, English Heritage has them in their souvenir shops, in two sizes - something approximating modern full-page size and half-size, akin to a bulky filofax. They have a leather cover with a rawhide wraparound thong to tie them shut, enclosing 140pp of handmade paper, resembling a thick vellum. It's obviously more "in period" than the elastic-bound waterproof A5 Moleskin notebook I've previously purchased for field trips.
If you can't get the embedded video to play for some reason, here is the direct link: