Very informative site on the history of vinyl. Goes into technical aspects as well.

Vinyl Record Collectors provides a massive amount of information covering the history of vinyl records ranging from Thomas Edison cylinder phonograph to the gramophone and then to the jukebox that will bring back memories of the 78rpm record, the 33rpm record and the 45rpm record, if you are a lover of the vinyl format and enjoy record albums/LP’s or vinyl records! Also covered is an extensive catalogue of vinyl online record stores from different areas from around the world.