Alright the browser (up top) where you're reading right now is where it will say, http://answers.yahoo.com,
In that line is the 'address of the site'.
Say you wanted to copy this one, just bring your mouse up to that address line, left click, - when it turns blue right-click. The option to copy should show up. Click that. Now the address, or URL, is on your 'clipboard, or stored temp. on your mouse until you paste it.
Then open up a new tab, or window, or even the answer you're trying to paste (put it into) and left click at the right spot.
Now right-click again, and you'll be given the option to 'paste'.
It's that easy. Try it in here a couple of times, and then try opening a new browser tab, or window, and pasting it into a new window. Then click Enter, and it will take you to the site.
It's not, hard, really - Just play with it.