SSL Help

I'm going to probably sound like an idiot. But I recently had to put down my old 10.3 server and upgrade to a 10.6 one and I'm trying to get a new SSL certificate installed for my main domain and I'm completely lost. I generated a CSR ok and then got a certificate from RapidSSL like I had done before. But when installing it's asking for a Private Key and a Public Certificate. Where do I get either of those? Nothing I can find in the RapidSSL docs makes any sense in regard to that and the Apple docs are confusing the hell out of me. Any help is much appreciated. Jamie