When you purchase an e-cig it will come in a box with a "charger" to charge it up....you buy the filters in a separate packet, they have normal, menthol, grape, cherry, all different types of flavors...they look just like a normal cigarette, only a bit heavier, the end lights up when you puff on it, mine is green!
Once you start to use it, it should last most of the day, and in the evening before I go to bed, I just plug it into the "charger" and it will be ready for use again the next day..its easy.
I love them, and switched to them quickly when I gave up smoking..if you have any more questions don't hesitate to ask.