I use Drive Image 7 [DI7] it is one of the best but is not cheap. There are cheaper ones, even free and other forum members will recommend what they use.
I will link you to a page that "Powerless" one of our own forum members has taken a lot of time to do. It goes into great detail both with graphics and text, its an excellent peice of work and would most certainly be allowed in this forum if the forum had the ability to import graphics.
Very easy to follow and well worth reading as many people do ask this question and Powerless has made it very easy to follow. please read it through fully and you will be able to backup your entire system or just parts of it to any media in no time at all. j.