It's easy to do, and you start seeing tons more NOBL coming into your wallets if you do it.

(First you need to create addresses to send to - it's real easy, "Receive coins" > "New address", but I'll do a real time HowTo tomorrow morning on that.)

http://asistec-ti.com/phpbb/viewtopic.php?f=10&t=134
http://asistec-ti.com/phpbb/viewtopic.php?f=10&t=135
http://asistec-ti.com/phpbb/viewtopic.php?f=10&t=137

If you don't see any of that, you need to enable coin control:

http://asistec-ti.com/phpbb/viewtopic.php?f=10&t=133