First I had some scrap boards (leftover from the desk my hubby MADE - he's awesome!) so that's the size I chose. It's totally up to you on dimensions. You'll also need fabric, corkboard, a staple gun, and picture hangers. First lay your board down on the cork to trace and then cut out a piece to cover the front of the board. Do the same for the fabric, but be sure to cut it bigger than the board because it needs to wrap the edges.
Lay your fabric right side down; center the piece of cork on it; place your board on top of the cork and fabric. Wrap the fabric around the board and staple the long sides. I love the PowerShot staple gun - I'm a whimp and I can use it. This process is just like recovering chairs if you've ever done that.
Now for the corners - staple the point down and then each side. See the picture - this will help your corners lay nice. Then staple down the short sides.