Nightstand about the same height as the top of your mattress or a bit on the lower side (to make it harder to bump your elbow). The bottom of the lamp shade should be about even with your chin level when sitting up in bed.
30 IKEA Hacks to Freshen Up Your Bedroom - Hemnes Nightstand: Underneath that paint is natural wood just waiting to get out. With a little sanding and gloss, upgrade the Hemnes side table into a stylish nightstand. (via Apartment Therapy).