Exceljet

What it is

Run by Dave Bruns, it covers over 500 worksheet functions with syntax, argument notes, and one or more worked examples per page. A searchable shortcut reference lists more than 200 keyboard shortcuts by category and platform. The formula section organises common tasks by outcome — count if, sum by date, extract text — rather than by function name, which makes it faster to reach when you already know what you want to do.