What is a proof sheet?

I am happy to report, that the proof sheets review was a success (missing numbers were never a problem ;) ), and I was given a permission to go ahead and publish the photos online, and even try to sell them (in case there will be any buyers). As a result - I have this: http://vzpix.zenfolio.com
I'll appreciate any advice about the looks, the pictures, or anything else you'd like to advise me about :D

Disclaimer: This message is NOT a shameless promotion of my new website!
Well... maybe it is, in a way :) I hope you don't mind :)

Becuase I bulk loaded my film from 400ft rolls I/we used foolscap paper and printed 40 frames or less if we didn't shoot the whole roll. Also one numbeered each frame with a number in indian ink. Does Irfanview renumber files, never needed to find out. One would have to assemble the pickies on a folder of its own and then re-number I guess.
Last time I did anything like this I had the numbers of the subject [ graves] to incorporate manually in the file number.
Some things are easier with digital :).

edit Good for you Vladimir.