Every rider should have some basic repair skills. The list of necessary skills will vary for each individual rider, but really should include common tire problem reprations. The obvious skills include regularly checking and inflating tires to proper pressure (check your tire side wall if not sure), replacing and repairing flat inner tubes, and placing a boot if necessary.
What is a boot you ask? I define it as a patch for the tire, as opposed to a patch for the tube. Flat tires are caused by punctured tubes, but sometimes they include a large hole in the tire as well as the tube. Patching the tube will not be enough to get you rolling again. The tire must also be patched or the tube will protrude out of the hole and simply puncture again.
Just for curiosity's sake I thought I'd see how common this term is so I looked it up in Wikipedia, and it's there. If you are nerdy like me and want to see click here. If you just want to know more about what to do when this occurs, just keep reading.
This may sound like a hard problem to fix, but it is actually easier than repairing the tube. All that is required is to place something large enough and durable enough (and thin enough) between the tube and the tire to prevent the tube from bulging out of the hole. There are several possibilities that will serve this purpose quite nicely. You can purchase something made specifically for this purpose, or you can use what you have on hand. Park tools makes something for this and they call it a boot. This item has one specific quality that isn't easy to come by, adhesive on one side to keep it in place.
If you haven't gotten around to buying one to put in your bag of tricks (saddle pouch), then you are left with what you have on hand. The next best thing is money, paper money. A dollar bill will do the job very well even though it doesn't have the adhesive. Here is a short video describing this concept.
I have only blown a hole in my tire once, but it was far less of a problem because I knew what to do about it. Now you do too...