Making backup copies of your data, fixing little problems, recompiling the kernel, installing software, and tweaking configuration files are not uncommon scenarios in every day GNU/Linux life: even if you don't do it all the time, some day you will want or need to. Those tasks can be managed without any hassle at all if you use a little common sense and follow some practices and guidelines we will introduce here. These will help you when those times come and you will have to solve more serious problems, like a system that hangs at boot time.