I've gotten used to generating and installing my certs with cPanel so I don't know how to do it any other way.

I was able to use gencert domain.com to generate the csr.

I ordered a comodo certificate and it came with three files.

www_aplusreunion_com.crt
GETCyberTrustRoot.crt
CommodoSecurityServicesCA.crt

I'm not quite sure what to do with these though. Any help would be greatly appreciated.

It's on a UNIX system running Apache.

Thanks!
Jeremiah