The last part of the actual bookcase itself is the top. Again, following the article's instructions pretty much as described worked out here. I did however decide to cut a wider top frame than described. I didn't see any reason all 4 pieces of the top frame couldn't be 2-1/2" wide so it was simpler just to cut them all to the same width. I mitred the from 3 -pieces (sides and front) but simply butt-jointed the back piece since nobody is going to see that anyway. The back piece only needed to be about 1" wide but I though the wider 2-1/2" width might make the top frame a bit sturdier even if it was probably overkill. It also seemed to provide a wider area in which to attach the top ply-wood piece. Either way it seems to have worked out OK.
I also decided to build up the frame separately (I didn't attach it to the top yet). I biscuited the frame together with a #20 biscuit. This allows me to build up the entire top frame, ply-wood top and edging separately from the rest of the bookcase. To me it seems easier to make all these pieces separately and leave the final assembly to the very end. Also I am not sure yet if I will apply a finish to the project before I assemble it or not. I am still on the fence about that part of it.
Once the top frame dried, I then drilled some counter-sunk #8 wood screw holes (8) around the inside perimeter of the frame. The purpose of these screws are to hold the top piece of ply-wood to the frame. There will be another perimeter of at least 8 screws as well doing down into the bookcase carcass. I will need to drill these once I am able to dry-assemble the bookcase again since these holes must be drilled to fit. Once attached the plywood top was trimmed flush against the top-frame with a flush-trim bit on my router table.
Lastly, I routed the same 1/4" bead into some trim pieces again and applied them to edge of the plywood top. The front edge has two miters, while the two sides are flush against the back. Each of the pieces of trim were cut to fit along the edge. Finally, the trim pieces were clamped and glued to the top-plywood piece. This finally completes the bookcase itself. The only part now which remains is the drawers. With just two weeks in the class remaining I think I am in pretty good shape.