Reading points: some matters to consider as you read:
Shakespeare's portrayal of the "other": Othello as an outsider.
As with Hamlet, illusion in conflict with reality: what seems to be vs. objective "truth." Misperception vs. intentional deception. Rampant irony!
Two different types of women: Desdemona vs. Emilia.
Shakespeare's commentary upon love: comparison with love in the comedies.
Iago's motivation: jealousy/envy vs. pure outright evil?
Iago's effectiveness as a villain: Iago as a masterful manipulator.
Shakespeare's portrayal of jealousy, "the green-eyed monster."
A different kind of revenge tragedy: comparison/contrast with Hamlet.
Othello as an Aristotelian tragedy: Othello as a model tragic hero, hamartia, or tragic flaw and all; also recognition and catharsis.
Thematic significance in scenes of comic relief: connections between adjacent scenes.
The question of how much we identify or sympathize with Othello.
Culpability: how responsible is Othello for his own downfall?