What is a good speed to read chess books at?

Let's assume I'm reading a densely annotated chess book (such as one from Kasparov's My Great Predecessors series). How many pages should I read per day in order to benefit from the book? At the very least, I imagine this depends on a player's skill level.

As much as you feel like.  Just make sure to take a bit of time to make sure that you understand what you are reading.  i.e. why the lines in the notes are important in their relation to the lines that were actually played.

At first that will take you quite a bit of time.   When my rating was 1400-1500 (USCF) then it might take me longer to understand the notes than it did the game.  By the time I was 1800 I started to understand much more quickly. 

So now if I study for two hours in a day the only difference is I get through a bit more.

Therefore my answer is to just go through as much as you feel like until you get tired/bored.

Readning a chess book is not a competition.

If you want to learn from the book, you should STUDY the book, and not just reading it.

If you don't retain little or nothing of your reading, it's just a waste of time. But of course you can read any book because you enjoy it. Even if you don't learn anything from it. Like any fiction book.

Bying lot of chess books is equal wrong. Lot of unread books on the shelf will not make you a better player.

I think it is best to take your time. I would rather spend a year or two on one book and get as much out of it as I can, instead of just rushing through it.