Anyone have or can give a good interupt tutorial?

I've found what appears might be a tutorial on interupts, unfortunetly its in french (

If some one has an english tutorial on interupts or can make a small one, it would be greatly appreciated. I'm not familiar with the syntax enough to make heads or tails of the functions in the interrupt.h file.

Currently I have the arduino set up to listen for an input constantly, which is a waste of power, and poor programing, especially when you are running it for days straight.

Any help would be great, thanx.