Basically with a self-signed certificate you just have to accept it the first time you connect to the website, and then, if later I'm being warned that the certificate is not the same anymore, then I can suspect there has been something smelly, and ask around about it.
In Chrome on Linux you have to accept it the first time, and Chrome will remember it until you shut down the browser. Next time you open the browser you'll have to accept it again.
I think going for a CAcert or a StartSSL certificate is a good idea.
Cheers,