Since there is the possibility for confusion here, I think a tutorial topic is in order.
Quoting posts is simple. Other users' posts will look like this:
To quote someone else's post, click the "Quote" button on the right:
You will be taken to the editor at the bottom of the screen, which functions as normal.
Quoted posts show up like this:
Clicking on the "Quote This" option...
...will allow you to add the post to the quotes system (which can be found here or at the top of the page).
It will show up in the editor like this:
However, please do not do this. The quotes section is currently for game quotes only. Feel free to contribute more quotes if they haven't already been submitted. Quotes need to be approved by an admin before they show up, so please be patient.