If you are thinking of running a Cthulhu roleplaying campaign in authentic New England surroundings, this site by John Ott has to be your first port of call. He's developed the Miskatonic railway line and in particular the city of Arkham as an amazing set of scale models. Show these pictures to your players to create a suitably eldritch mood.
For other things nameless and redolent of the outer darkness, try:
- The H P Lovecraft Literary Podcast
- Voluminous (the podcast of Lovecraft's letters by the HPL Historical Society)
- Lovecraft's fiction (but be sure to avoid Derleth's mythos contributions)
- Cthulhu Dark RPG
Or even this write-up of our 1890s campaign, which (I am told) was loosely based on "The Night of the Jackals", a scenario in later editions of Cthulhu By Gaslight.
