There's first of course, the famed University of Gwylin Press, then the guys who print the Black Horse Courier, also the printers of the "Common Tongue" in Mournhold. I think we can assume that Tamriel has a fairly well-established printing/press infrastructure. I vaguely remember that the "Common Tongue"-hideout even had a printing press model in the game - I can't check that right now.
There are no printing press models, but I remember a mod that added one two this place.
With the tons of books being sold in the Empire's economy, I'm sure they are printed.