Step 1: Materials
I purchased my magnets from K&J Magnetics, Inc. A direct link to their product page where all of the magnets can be purchased is here: http://www.kjmagnetics.com/products.asp?cat=10 . The amount and type of magnets that are needed are:
20 x 1/4 diameter, 1/8-inch thick neodymium magnets (Part D42) -- For the underside of each hex
20 x 5/16 diameter, 1/32-inch thick neodymium magnets (Part D501) -- For the top of each hex
1 x 3/16 diameter, 1/32-inch thick neodymium magnet (Part D301) -- For the thief
1 x 1/8 diameter, 1/16-inch thick neodymium magnet (Part D21) -- For the thief
You will also need a sheet of sticker paper to attach numbers to the magnets. I purchased 3" x 4" sticker sheets from an office supply store.
**Note of Caution**
The magnets are very strong, so be careful around magnetic equipment and electrical equipment. They are small enough that they should not severely pinch your skin, but it is best to practice caution.