I have heard the mermaids singing
information commons about "The Love Song of J. Alfred Prufrock" (1917); includes a fully-proofread and printer-friendly text-only version with bibliography, hyperlinks as well as discussion forum.
Prufrock and Other Observations
Several poems online.
Prufrock Notes
offers a brief explanation of the poem
Prufrock, Lazarus, and Michelangelo
extensively illuminates each allusion in the poem