Learning to touch type properly. A short course I took in the summer pays off every time I use a keyboard, which is all day.
The other one was a summer course in basic accounting that taught the basics of double-entry bookkeeping, balance sheets, and income statements. That has paid off literally, ongoing, and well. Very good investment of time.
The other one was a summer course in basic accounting that taught the basics of double-entry bookkeeping, balance sheets, and income statements. That has paid off literally, ongoing, and well. Very good investment of time.