Press Alt with the appropriate letter. For example, to type € (euro symbol), press Alt + E; to type £ (pound symbol), press Alt + L.
Stop the mouse over each button to learn its keyboard shortcut.
Alt + click a button to copy a single character to the clipboard.
You can select text and press Ctrl + C to copy it to your document. In your target document, press Ctrl + V, or, if you want to paste the text without formatting, try Ctrl + Shift + V.