The Romantic Audience Project presents information about the composition of the "Ode to a Nightingale," as well as plenty of scholarly rabbit holes to get lost in.
"A collection of resources dedicated to the second generation Romantic Poet."
This is a handy website for anyone studying the 19th century (not just the Victorian Period, which is only from 1837-1901). This is the link to the John Keats portion of the site, which has a biography and timeline of his short life, as well as other great resources.
The British Library in London is one of the largest, most important collections in the world. Even if you can't visit in person, their website provides some useful information about the writers whose manuscripts are kept there. This is a link to a British Library page about John Keats.
Readings of some of Keats's most famous poems, including "Ode to a Nightingale," brought to you from the BBC.
"Poets on Poets is an audio archive of Romantic-period poems selected and read by practicing poets from around the world."
A musical recording of "Ode to a Nightingale," "Ode on a Grecian Urn," and other poems.
Listen to an actual nightingale.