Heads up to the current issue of Rail Magazine. It's an issue focusing on small and medium size railways (and some third sector), including a very nice profile of the Kanagawa Rinkai Railway, as well as the freight action in the Tsurumi area of Kanagawa Pref. But the best part is a insert with string diagrams for most of the railways described in the issue. Especially useful are the diagrams for the Chichibu and Sangi Railways, with their relatively frequent freight services- helps greatly for positioning when on photo shoots.
http://www.neko.co.jp/?p=18040