The body needs about 2-3 litres of water per day. That includes all the water in food as well, so fruits and stuff with a lot of water, as well as boiled pasta and grains, supply a fair share of the daily water intake.

When I ride, I consume about half a litre per hour at endurance pace, i.e. where energy intake and time limit my ride distance. At faster speeds, I need more, but I generally only last for less than an hour then, so drinking can be done before and after.