Whatever your artistic endeavours, you can never have too much reference material. Although I use Pinterest nearly every day, you can’t beat a good, well collated reference book, particularly ones aimed at artists and animators.
On my last trip to Japan I picked up the first book in the Background Visual Material series – Factory Area & Complex (背景ビジュアル資料1 工場地帯＆コンビナート), published by Graphic-sha. This volume is a brilliant collection of Factory complex/industrial area photography. Aimed squarely at animators, illustrators and CG artists, it’s the best single volume reference I’ve ever seen on the subject and is a must-buy for CG/environment artists.