Ah! Finally I am able to see my hard work assembled as a functional bookcase. The first step at this point was to glue together the drawers which I cut to size earlier and cut locking rabbet joints into. This was a pretty easy glue up. The locking rabbet joints hold the pieces together really well and make drawer assembly a breeze.
The photo below shows a close-up of the locking rabbet joint. As you can see it seems very string and holds together nicely.
Shown under that photo are the sub-assemblies ready for a bunch of sanding.