Try searching older posts.... this issue is a common one. One issue you need to decide is whether you are running off of "mains" aka shore power aks house power aka 120vAC (or 220vAC in the EU, etc) or if you want to use battery power, solar power, etc.
Canon makes an AC power supply that uses a transformer and a dummy battery to connect. I think it is the ACK DC20, if I am not mistaken. For less money, people have made DIY wooden dummy batteries, and acrylic/plexi ones as well and wired up things themselves. It just depends on what your needs and budget (and skill level) are. Good luck.
