Look at this poor and sad car. It can't start because its battery is dead, nearly dead. So, what shall we do? Lets look at the first step.
(Thank to papertoys.com for the paper cars in this instructable and crazyscientist_11 on Flickr for his photo of the engine bay, I used with his agreement.)
Step 1: What you need:
a car with a low battery to jump start
a booster car (to jump start from)
instead of a booster car you can get a booster pack like the one on the picture beneath, which contents also a light you can use in the dark (very useful).
a pal to help (not needed but also useful and in the most cases attached to the provided booster car)
Step 2: Detrmine if battery is dead
The easiest and fastest way is to check the clock in your car, turn the light or the wipers on. If they will work - there is another problem, but not the battery. If you turn the key an it cranks steadily - maybe it is not the battery, if it cranks slow and not round (tsh . . . tshsh instead of tsh tsh tsh tsh) or you hear no sound at all - jump start.
In our case you see the car is so sad it must have a dead battery, it can mourn about.