Best software for anonimity - easy to use

Does anyone use anonimity software, and if so which one. I am looking for one that is easy to set up and use. I don't want every Tom, Dick and Harry knowing my IP address and would like it to change randomly to give me privacy. I am not doing anything illegal, just want to use some forums such as this one without being tracked every time.

I notice that I have a local IP address and an ISP address from the server, what is the difference please and can both be "hidden"

Thanks