How To Copy and Paste:
Take your mouse, and place your cursor at the beginning of the text in the box below, then click and hold the left mouse button, while pulling your mouse over the text. This should highlight the text. Now release the left mouse button. Now, with the cursor over the highlighted text, right click the mouse for options, and select 'copy'. Now over the empty box below, right click your mouse again, and select 'paste' and you will have copied and pasted the text. :-)

Copy this line.

Cut and paste is the same as above, except you choose 'cut', instead of 'copy'.
Shortcuts
To Highlight: Press 'Ctrl' + 'A'.
To Copy: Highlight an area, as shown above, then hold 'Ctrl' + 'C' (For Mac users 'Apple' + 'C').
To Paste: Click your mouse where you want the text pasted, and then press 'Ctrl' + 'V' (For Mac users 'Apple' + 'S'.

The ability to cut, copy, and paste is found in most programs. Sometimes, the ability to do these tasks via the mouse is disabled, but is still quickly achieved through the use of the shortcuts outlined above.