I just use it for internet and stuff but I would just like it to be faster for file transfer and things like that.
Seriously, a dual core 4800+ is way more than you need to surf the Internet and do file transfers with, even without overclocking it. If these basic things are slow, check the computer for malware and do simple things like defragmenting the hard drive. Is there plenty of free drive space? How much free memory etc. Just a thought. Overclocking also generates extra heat, if you could do it the cpu stock fan may not be sufficient. This is more for hardcore gamers who just want that extra bit more out of the hardware. It's probably not what you really want to be doing, it doesn't sound like.
Here in Tampa where it's usually too hot and the bugs and gators are usually too big. Tampa Computer Repair