Generally I say to stay away from overclocking laptops. It's a quick way to void your warranty and then melt your laptop into your legs.
If you do what to try overclocking though, download yourself either RivaTuner or MSI Afterburner and increase the clock speed by just a little bit. Each time you increase the speed, test your temps by running FurMark.
It's a laptop.. if you need more power for games then I suggest getting a tower computer and keep your laptop for facebook