Anna Warren just pointed me to this incredible resource:
The Properties Directors Handbook: Props for the Theater, written by Sandra J. Strawn.
There’s a lot of information here. It’s more like a book than a website. Everything you wanted to know to get started as a properties director is here. It’s also one of the most up-to-date resources on props, and it’s extensively illustrated as well. She includes photographs from a number of professional theatres across the country, such as Actors Theatre of Louisville, Milwaukee Repertory Theatre, The Guthrie Theatre in Minneapolis, and the Seattle Repertory Theatre.
It’s so good, I’ve added it as a permanent link on the sidebar.