Bartleby
Bartleby.com: Complete Poetical Works: Percy Shelley
This site provides links to all of Percy Shelley's poetry, with a search function. It also offers notes at the beginning of each work.
Bartleby
Bartleby.com: Cambridge History of Eng and Am Lit: The Romantic Revival: Shelley
This site has links to literary criticism of selected poems by Percy Shelley and other Romantic-era poets and writers.
Other
The Keats Shelley House: Percy Bysshe Shelley
This site provides a biography of English poet Percy Bysshe Shelley. It contains quotes from some of his most famous works.