Work-search log: how detailed does it need to be? - 10 months and counting

I have been applying to about 18 jobs a week as a quality inspector, but I am unsure what my state wants in the log. Any experience at all would help. Some days I only network by email or attend a job fair. What do you record?

Screenshots of the submitted application are handy backup when a posting disappears.

I was asked for my log once, after six months. Having it in a spreadsheet made it painless.