Listen to the full text of the poem read aloud for free at LoudLit.org.
This website for the BBC miniseries "The Romantics" has free audio readings of "Ozymandias," as well as selections from "Queen Mab" and "Adonais."
The Romantic Audience Project at Bowdoin College provides access to this scanned image of Shelley’s manuscript for "Ode to the West Wind."
This version of the poem, first published in Arthur Quiller-Couch’s 1919 anthology, the Oxford Book of English Verse, has very different punctuation and capitalization from that found in modern editions.
This is the poem as it was published in Francis T. Palgrave’s 1875 anthology The Golden Treasury. Try comparing this version to the one in the previous link. It’s interesting to see how different the poem feels with simple changes in line breaks, formatting, and punctuation.
Google Books provides free and complete access to this four-volume 1892 edition of Shelley’s poetry.
This annotated edition from W. W. Norton includes lots of useful background material on Shelley’s life and the history of his poetry.
This edition of Shelley’s poetry from Oxford University Press is inexpensive and authoritative.
This site, managed by David J. Brookshire at the University of Maryland, is a great place to begin your research on Shelley.
An online copy of "Ode to the West Wind" with notes and commentary by Prof. Elizabeth Fay from the University of Massachusetts, Boston.
Hosted by the University of Toronto library, this page includes the text of the poem, footnotes, and commentary by Ian Lancashire.