I think everyone should drink 8+ cups of water atleats per day. I drink about 1.5-2 liters, plus about 3 cups of tea a day. Thing is about water is at first it may be difficult to increase your intake and drink a lot more at first, but after a while your body will learn to crave it.
It depends. When you're active you need more than 2 litres, inactive and you can get away with less. Generally 2 litres are recommended, however this also depends on your lifestyle. If you drink lots of teas and other drinks you need less (cafeine excluded).
For younger people and those who are very active (like under a special training) then it should be as many 3-4 liters. For average people: take minimum 2 litters to have healthy kidneys :D
I tend to drink 1.5 litres a day plus tea, I have a 1.5 litre bottle that I fill up everyday, I find it easy to keep around me which makes sure that I get my daily intake.
You should drink at least 2 litres everyday, whether its mixed with juice or tea or whatever, or just plain water :)
I believe 8 (8 oz.) glasses per day is recommended.
8 full glasses