Here is how to sight:
http://www.feelforthewater.com/2011/06/how-to-sight-correctly-in-open-water.html
Essentially, lift head to crocodile eyes, drop head and turn to breathe at the side as normal. So you do it just before a breath. Head has to go higher than crocodile eyes if there is chop or people in the way.
There is a knack to it. When you get good at it, you can sight pretty much without slowing down in flat water.
It is easier to sight on high up things directly above wherever you’re headed to get a general direction, but as you’re getting closer to whatever you’re actually headed for, you do really need to sight on that.
Don’t follow people in front without sighting too, as they may be zigzagging idiots.
If you’re rubbish and not in a hurry, you can just breaststroke a stroke or two to sight, although breaststroke is harder in a suit.
Oh, and one random useless sighting tip from last night’s swim, if you’re swimming at night, and you put a light to mark where you left your clothes so you can see where to stop, don’t put it in flashing mode, as it will only be visible if you sight just as the flash goes, I was seeing my light only on about every 5th sight!