Intel tuning is a program designed to allow you to overclock your processor and other components.  As for if its safe, to a degree yes.  you can take a 3Ghz processor and overclock it to 3.6Ghz without much if any problems for the most part.  Most people go on forums and see what others have done.  The biggest risk you have is if your cooling system cannot keep up with the extra heat dumped off the processor or memory and then you risk frying your system. 

Dell recommends only using the AutoTune feature and that you choose the 1st option, "Stay within the manufacturer's limits". If you decide to use the Manual Tune feature, users should be knowledgeable about advanced PC hardware settings. Improper settings can permanently damage the PC.