How to clean marks from masking tape glue on the windows

A good brand of orange oil (limonene) cleaner takes care of most of my tape problems. Some tapes, such as window-tinting sheets, are thermosetting, and removal requires heating. I used a clothes steamer/razor blade on the tinted windows of my Honda. That worked well. See method two, here.

Black ink newspapers work but they are messy and difficult.

If you have a lot of glass to do, duplicate how the professionals do it. They use dishwashing liquid solution (not an ammonia based glass cleaner like *%$dex). They use a soft absorbent scrubber (you could use a soft sponge mop maybe?), then they use a good quality squeegee to remove the grimy liquid from the glass. Follow that up with a quick dry rag wipe of the edges and corners.

You might think about blasting all the windows with a water stream first, to remove as much loose dirt from the sashes and mullions as you can.