That depends on what you want to do!
For day-to-day, that's probably correct. If you're intending to drain the pool through the main drain, then the handle should be at 9 o'clock position. If you're vacuuming, you might need it set to 6 o'clock. Essentially, the shape of that handle - where it says "off" - is the same as what's inside. So you can see what it's blocking off.
EDIT: see posts below