Through experience and education I've learned that staying hydrated isn't that complicated. Like others have said above, drink water when your thirsty, that will do the daily trick.
On day's when your hitting a workout hard; make sure you drink a pint or so about 2 hours before your workout. That way you'll have to pee an hour or so before to help flush out stuff you don't need and you'll be sufficiently hydrated at the beginning of your workout. During your workout make sure to drink periodically, but not necessarily after each set or exercise. Try setting your workouts into rounds and hydrate in between rounds (intensity/ volume will dictate how often you drink)
One key, is to not sip the water during a workout. Most just sippy sip because they worry about stomach cramping and discomfort. Truth is though that if you're feeling that discomfort then you either already are or are on your way to dehydration-ville.
So why not just sip consistantly throughout the workout? Well, your stomach won't empty until there is enough of something inside to trip the trigger. Somewhere between 4-8oz at a time should be enough to get the job done. When your stomach empties that much fluid, your body knows exactly what to do with it.
Think of it like this. If you're driving your whip on "E", and you stop every mile and dump a splash of fuel in the tank. It is not very efficient and you won't get very far.
Remember:
think good, eat right, work hard
BC