Normally if it's a real certificate you needn't to include it in your web browser since the root certificate should be present there.
Keep your private key secret!
First you will need to generate a Certificate Signing Request (CSR). First of all generate a key (Verisign demands a paswordless CSR):
openssl rsa -in server.key -out server.key.insecure
Then generate the CSR:
openssl req -new -key server.key -out server.csr
Now hand it over to Verisign.
Put Verisign's root certificate in
Download the intermediate certificate here and put it in the same folder as the root certificate. .
Now add a vhost for your https, your IP is 188.8.131.52 and your site is located in /var/www:
Enable SSL with
a2enmod ssl restart apache2 en you should be allset.
Refer to documentation at: