Here we have a flat tire. First thing you need to do is remove your wheel. Remember, safety first.
Now we need to locate where the leak is coming from. If it's not obvious or you cannot find any foreign objects sticking out of your tire, you can inflate the tire and run some water over the tire and look for bubbles escaping from the hole.
Of all things to put a hole in your tire, we find a house key. Use some pliers or vice grips to pull the object straight out.
Here is everything you will find in a tire repair kit. Make sure you buy the kit since it comes with the tools you will need to fix that nasty hole.
Take the tool that has the pointed tip and ream out the hole. Put a couple drops of the rubber cement supplied in the kit to the end of the tool. This cleans out the hole and gives you a nice surface for the plug to adhere to.
Grab the other tool and slide a plug inside of it. Be sure not to get the plug dirty. These plugs are very sticky.
Put some rubber cement on the hole and a little on the plug itself. Don't use too much. Then push the plug into the hole about half way. Now slide the tool out of the hole.
This is what it should look like.
Our hole required two plugs. If you need to use more than two plugs, then you will need to replace the tire as soon as possible.
Let it sit for a few minutes and then cut off the excess material making sure you leave about 1/8" sticking out. Now you can inflate your tire.
It's a good idea to have one of these tire repair kits in you trunk along with an air compressor. This air compressor plugs right into your cigarette lighter and has a light. The plugs used in the repair kit are meant to be a temporary fix. I have seen them last for thousands of miles but it would be a good idea to replace the tire.