Here is a list of online resources relating to the Herculaneum Papyri. Some are in Italian or German but the essential information is usually accessible without extensive knowledge of the languages.
CISPE, the international centre for the study of Herculaneum Papyri in Naples. Includes overview of the Content of the published Volumes of Cronache Ercolanesi and La Scuola di Epicuro.
Bibliography on Philodemus of Gadara (Oxford Bibliographies Online). Subscription required.
Online catalogue of archive of the Officina dei Papiri
Published engravings of Herculaneum Papyri: Collectio Prior; Collectio Altera