Need help with proxies and IP's

Hey guys, I'm a noob and this might be a dumb question but I need help figuring out how to use different proxies/ or ip's for facebook profiles. I am looking to create 5-7 fake facebook profiles and I have firefox as my browser as well as FB friend adder. I want to use pics from plentyoffish but I am worried about my IP being detected, kinda paranoid about it. This is my first time doing this so can you guys help me understand what I need to do to use different IP's and where I can get different IP's? I'm confused here, Thanks