I recently started building two Steel String Guitars.
To get the sides and backs I needed, I cut pieces of about 5mm thickness off a thicker board. This is done on the bandsaw which is equipped with a fence to guide the blade of the saw and make sure the cut is straight and the thickness of the board is going to be even. Because my saw is rather small for this task, mounting and adjusting the fence is crucial and takes quite a bit of time and patience.
The result is a back and sides of Pear and another set out of Walnut. The next step will be to sand the boards to thickness and to join them.