Although you might find a good bit of information on these lenses in standard applications for movie cameras, you probably won't find much hard information on using these lenses reversed on larger 35mm format film. Most are in the C and D mounts that Kino mentioned, and you can find those dimensions on the web with a little searching. But since you're reversing them, you'll probably have to make a custom setup for each one.
The best source for them that I'm aware of is drying up fast, and those are old-line photo stores that haven't cleaned out and tossed stuff from the junk boxes and drawers in the back room. Currently you might have better luck at second-hand thrift shops finding them on cameras. I got a handful for a few dollars about 20 years ago, but haven't put them to much use except in front of a web cam or as telescope eyepieces. I did get a used bellows a month or so ago, so I now have a better way to utilize them.
Sorry I can't give you any hard info, but I think the best you can do is scrounge some and experiment to see what gives you the best results.
Edit: just saw the last post, and the reason for the odd mm sizes is that the mounts were specified in inches IIRC. I believe the C mount was 1 inch x 32 tpi and the D mount was something like 5/8 inch, but I don't recall the thread spacing. But my memory may not be too reliable, so check good sources.
And I just found this: A C-mount lens produces a focal plane 17.52 mm behind the camera's flange, and a CS-mount lens produces a focal plane only 12.52 mm behind the lens flange.