Overclocking may not be as difficult or dangerous as most people think it is, but it still has consequences. If the only thing you'd do was changing the frequency/multiplier of say, a cpu, then the only danger would be a non booting pc if you go too far, which can be remedied by simply clearing the cmos settings. However, most overclockers drive up the voltages used to get higher stable speeds and this is when you get extra failures due to overheating and especially a shortened life expectancy for the cpu (due to increased electron migration).
I have encountered examples of people who overclocked their cpus for 2-3 years, and then had a boot failure. The thing is, even when clocked back to the original speed those cpus wouldn't boot anymore, but they would boot if you UNDERclocked them by enough difference. They were "worn out". So there IS a price to pay for overclocking, however since a cpu rapidly loses its value anyway (three years and even the most advanced system won't cut it for games anymore), it might not matter enough if you keep from the truly insane overclocks.
But if you don't feel comfortable overclocking, don't try it. There's no law that says you HAVE to do it
