I found this old video of mine I took about a year ago tonight. I added some sneaky Splinter Cell music and a title. I figured I should not let it go to waste. It shows dimensions and pretty much everything you ever need to know in order to make shims. Sorry about the camera work, it was a photo cam not a video one and I had to set it up on a flat surface and work in front of it. When I was trying to figure out how to shim a padlock for the first time, I would have loved to have something like this spoon feed me everything. For all the noobs out there, here's your easy fix

! I hope this helps, let me know if you like it!
PS: Remember, the measurements are just rough estimates. This doesn't have to be perfect in order to work. It also depends on the size of the padlock you are trying to open. This worked fine for a common Master combo lock.
http://youtube.com/watch?v=oQx3iSebpJU
Kaotik Edit - Cleaned up post