Make 4 x's, in pencil, near each of the 4 corners of the wooden board. Each x will mark the center of each leg of your wood desk. The x's should be in identical positions at each corner.
Center a leg against one of the x's. Nail the board securely to the leg through the top side of the board. You will need to use 3 or 4 nails. Repeat for the other 3 legs.
Stand the table up on its legs. The table should be even. If the table is not even, sand the bottom of the longer leg.
Fill the nail holes on the top of the wood desk with wood putty. Use sandpaper to finish.
Sand away any rough spots on the top and sides of your wood desk. Stain the finished desk in your preferred color. You may also use a clear stain. Staining helps to protect the wood.