Classic Technology Center: Study of Poetics
http://ablemedia.com/ctcweb/netshots/aristotl.htm
Comprehensive study guide that includes articles about historical context of The Poetics.
Study Guide: Poetics
http://faculty.goucher.edu/eng211/aristotle_poetics_examples.htm
Provides a systematic breakdown of Aristotelian concepts - good for the reader who needs a review of key terms.
Aristotle's Poetics: Annotated Edition
http://www.perseus.tufts.edu/cgi-bin/ptext?lookup=aristot.+poet.+1447a
A clear translation of the text, accompanied by margin notes for all relevant concepts.
Aristotle's Poetics: Summary Notes
A very brief introduction to the text for readers new to Aristotle, with a clear explication of all key term
Complexity and Pleasure in Aristotle's 'Complex Plots'
http://www.english-literature.org/essays/aristotle_poetics.html
Offers a comprehensive discussion of 'complex plot' and tragic imitation.