That is a personal question for everyone as everyone's situation is different. If you could put 20% of pay checks / earnings away that would be great. If you could only do 5% or 10% that is good too. If a set amount is automatically put away its like you never see it so you don't miss it and it accumulates faster than you would think.
Also learn early that credit cards aren't free money, pay them off every month. If you are debating about getting something you can't afford (gaming system, bike, that cool new $200 jacket),wait a month or two until you can save for it to get it.