The short version
- Red to red, black to black. Dead car positive, good car positive, good car negative, dead car negative to bare metal.
- Start the good car, wait two minutes, start the dead one. Remove the leads in reverse order.
- Never let the two clamps touch. Never lean over both batteries at once.
Do this today
Find your jump leads and put them in the boot. Then look at your battery and find the plus terminal, so you know which one it is before it is dark and raining.