Despite its somewhat dubious reputation (thanks wholly to the low-end commercial furniture industry), the technique of doweling, if executed properly, can be a strong and secure way of joining two pieces of wood together. Accuracy is key, or else the joint will either fail or not come together at all. Shown here are two (out of three, one for each side of the cabinet) of the doweling jigs, which essentially serve as drilling guides.
The cabinet top and bottom, with dowel holes drilled. Each "guide" (basically a scrap of wood with a small "heel" glued onto one end) is used to drill holes in both the sides of the cabinet, and into their corresponding locations on the top and bottom pieces.
Once all the dowel holes are drilled, a few dowels can be inserted to check for alignment. (And , of course, to have a look at the way things are shaping up...)