Cutting paper from a roll

Hi guys
Since I want to do some paper negatives with my shedload of Kodak Supra III, I would like to cut some 8x10 sheets off of my 20.3cm x 80m roll.
But I do not know how to do this. Do any of you guys(and girls)?
Thanks
Ektachrome

Fix a guillotine to the table, clamp a stop 8" away parallel to the guillotine's blade. In total darkness, unroll a length of paper and start cutting.

(there was a url link here which no longer exists)

I cut color paper all the time under a #13 safelight. It's pretty dim, but you can see what you are doing. I've never had any problem with fogging either. I have a little stand I made to hold the roll of paper and I feed it across to my paper cutter. I set the stop for the size I am cutting and move right along. When I cut 4x5 paper, it goes very fast. I can do about 300-400 in an hour. Larger sizes go a lot slower.
Make sure the paper is straight in the paper cutter. It's very easy to cut it crooked.