A doweled joint is one that is strengthened by the use of wooden pins or pegs which are called dowels. The use of dowels strengthens the joint considerably.
You can buy them ready cut from any woodworker and shape them to exact size, or you can make them in a workshop in a dowel plate. This is of steel, about 1/4 inch thick with several round holes of different sizes.
Roughly prepare the wood, selecting hardwood for dowels, and force it into these holes. Dowels must be smaller than the wood to be joined so that they will slip into the holes prepared for them without splitting the wood.
To glue and dowel a joining, first be sure the edges are square and then join the edges in a vise and mark with a pencil the exact place where the dowel holes are to be made. Bore with a bit to a depth twice the diameter of the dowel. Cut dowel pins of proper length with a saw and round the edges with sandpaper and make shallow grooves so that extra glue may run out.
Apply hot glue to the dowels and the boards which have been warmed in advance, slip the dowels in place in the holes already prepared and glue between the boards. Allow them to stand in a vise until dry.