Peyton, I never scan anything as a JPEG. JPEG is a poor format for anything but images on the web. I always scan as a Photoshop file and then make a TIFF or JPEG depending on where I want to use it. If you scan the Photoshop file at high res, then you can normally resize it with little or no loss of quality.
I do not scan many magazine pages, but when I have, I took the staples out and took it apart. I would never cut the pages unless the magazine is a throw away.
I wrote two commercial books on scanning, but that was long ago and they are too out of date to be useful.