Before jumping in to this project, I suggest reading up a little on board dimensions.
Step 1: Select your wood
Step 2: Rough cut the frame
Step 4: Cut the sides of the frame to length
Step 5: Fit and measure the frame, glue up the top
Step 6: Cut the top to size
Step 8: Fit the bottom
Once the bottom is on and fastened, find the center of it by drawing a line from corner to corner. This is where you will cut the resonating hole like an acoustic guitar.
Step 9: The hole
Step 10: The grid
An interesting fact about gobans is that the grid is not acutally squares, but rectangles. They are "optical squares" so that when sitting at a goban looking down on it they look like squares due to perspective. I suggest reading about it here before you start marking up the board. I found it invaluable to make a full size version of my grid on a piece of butcher paper before going for it on the board itself.
Once the final dimentions are figured out, transfer them to the board. I chose to make my grid using a veneer trim saw, which is the perfect width to make the scores. The alternative is to use a permanent marker and not score the grid. I kept my lines strait by using a T-square and a clamp on the other end.
Step 11: Finishing touches
The board should be sanded nice and smooth, removing all spliters etc.
Next step is to choose a finish. I went with a mineral oil finish to bring out the colors of the woods I chose. I decided not to lacquer it, because I want it to breathe.
The final step is to add rubber feet to the corners of the board. This elevates it so that the acoustics work. You can pick these up at a hardware store.