Does anyone scan pages from art books and the like? I am wondering how you do it. I need to scan a Japanese book and it's quite challenging to open the book up to get the full page scanned.

I'd just try to find some scans on the net.

I wouldn't even attempt to do this with one of my artbooks for the reasons you stated.

Getting the page to line up with the glass would require you to compromise the spine of said book... and over time... don't even want to think about it.

For example I think most of the Mega Man artwork has been uploaded on to the Mega Man Wiki page... so I'd just go there for it even though it's probably not in super hi-res.

Sometimes I scan music books.  I have a Plustek book scanner, which has the document glass go all the way to the edge so you can just open the binding 90 degrees and place it gently on the glass.  The thicker the book is, the harder it may get the spine all the way up to the corner of the scanner glass, depending on the binding, but even though the software it comes with is a little annoying, the results are great for the price.

animepaper.net used to be one of the best places for high res artwork. I have yet to find a place that has such a great library of scans. Nowadays I use,

http://www.creativeuncut.com/
http://www.minitokyo.net/

Other than that, all my resources have died a while back.