Re:
oh...you mean Electro Static Discharge?
Yeah...ESD is probably the only concern. Be sure to ground yourself by either operating on your PC on a anti-static mat, wearing an anti-static wrist band or simply by keeping hold of the computer case while working on the insides- this only works when your PC is plugged to a power outlet, but the mains turned off.
Also, try to avoid touching any metal contacts (such as on the circuit boards, pins and plugs etc...).
You should also meake sure that any components which are taken out of your PC should be placed on a non-static surface. Such as an anti-static bag.