Pablo Stafforini's page has many many online books and papers by and on Hume, Godwin, Bentham, the Mills, Sidgwick, Hare and Singer.

The Classical Utiliarianism Website CUWS at Texas does not seem to be updated any more.

The Bentham Project at UCL also houses the International Society for Utilitarian Studies.

The New School for Social Research has a comprehensive website on the history of economic thought. The comparable site at McMaster University is also excellent.

More soon !