If you are unsure or feel as if the procedure is too dangerous or complicated, by all means get someone who is knowledgable to help you so as to prevent injury to yourself and damage to your car. If you know that you have left your lights on and you are reasonably sure that your battery and charging system are in pretty good shape you can just jump-start your car and be pretty sure that it will recover from the temporary problem you have encountered. This article deals with the simple and safe steps to get you started and on your way. You will need a few essentials before attempting this task. First, you will need a good set of jumper cables.
Good cables have multiple stranded copper wire, about four gauge.
It usually says it on the box. Soldered connections are best but a really good crimp will suffice. When you buy jumper cables go for the extra buck and get them longer than your car so that you could possibly get a jump-start from someone parked behind you. It helps if you open your hood and stand there with the jumpers in your hand with a sad, forlorn look on your face. I have jumped my own car using a John Deere garden tractor.