On your intended webserver, install mod_ssl via yum or whatever your package manager is.
# Change to the /tls/ directory
$ cd /etc/pki/tls/
# Create a new encrypted private key
$ openssl genrsa -aes128 -out private/httpdkey.pem
# Input a password you'll remember as prompted
# Generate a self-signed certificate using the encrypted private key you just made
$ openssl req -new -x509 -key private/httpdkey.pem -out certs/httpdcert.pem -days 365
# Input passphrases as previously prompted