NameVirtualHost [your IP address]:443
<VirtualHost [your IP address]:443>
  ServerSignature On
  SSLCertificateFile    /path/to/the/certificate/from/your/certificate/company/apache.crt
  SSLCertificateKeyFile /path/to/the/file/created/in/step/1.key [can be a .pem file too I think]
  SSLCertificateChainFile /path/to/intermediate/cert.crt [optional, only if your certificate company provides you with one]
  SSLEngine On
</VirtualHost>