Do the drawers need to be assembled as well? How many actual pieces come for one drawer?

Our drawers require simple assembly. Drawers come with front, back, side panels, drawer front, knobs, and hardware.

What are the inside dimensions of the drawers?

The internal dimensions of the drawers are:
Height, 5.5"
Depth, 13" 
Width, 19.5" unit - 15.75", 25.5" unit - 21.75", 31.5" unit - 27.75".

Can I not have the knobs? I would like to match what I have in the rest of the house?

Our drawers will automatically come with polished chrome knobs at no extra charge. You can use your own knobs without voiding your warranty as long you use our pre-drilled holes only.

Are the drawers full extension?

Yes

are glides included with drawers?

Yes