I select subjects by watching new books uploaded to the Public Domain. I monitor the Texts library of the Internet Archive (IA) by getting a list of All Items (most recently added first). This means that, on a daily basis, I glance at nearly 1,000 new entries -- screen after scrolling screen of new entries uploaded to IA's online repository, which already has some 3.8 million books.
The sheer volume of this daily load -- I'm retired, remember? -- pretty much eliminates any clear strategy of subject selection. Of the day's thousand new entries, many can be eliminated. Some, like sheet music, tidal charts, essays, have no suitable images. Some are court records or have digital rights encumbrances like passwords or annoying interfaces like Google Documents. (I sometimes get around Google by using the Google-free search above and then sorting results by "Date added.") Language is not the barrier: I freely use images from books written in languages I don't understand.
Anyway, when I finally find a document that is (1) accessible and (2) has images -- maybe two or three per day -- well, that determines the subject. I don't start out the process thinking "I'll do a piece on religious fanaticism today." I find something on that subject, or on European marble cutting, or early steam boiler design -- and I go from there. It's random. It's closer to the experience of my professional life as an assignment reporter -- you never knew what you will be writing about.
12/6/2012