You'll need 2 pieces of coordinating fleece. For my hat, I used solid black for the cuff, and a sports print for the body of the hat. I have an embroidery machine, so I stitched his name onto the black fleece before I started assembling the hat. You can do the same or something similar, or simply ignore the instructions about the embroidery.
The fleece for the body of the hat should measure about 22" wide by 12 inches tall. This will vary depending upon the size head you're trying to fit. I've found that 20-21" is about right for young children. If the head you want to fit is readily available, just measure it and add about 2" for working space.
The fleece for the cuff should measure about the same 22" wide, by 7 inches tall. If you're embroidering a name, the name should be stitched about 2-3 inches from the bottom edge of the fleece.
You'll also need two pads of fleece for the ear pads, measuring 3x5" each, and you'll need matching "fluff" for the ear-side of the cuff. I used a modern terrycloth, like what they often use sometimes for women's bathrobes. It's heavenly. I want to live in it.