Create an SSL Login for Your Website

Do you have a website, but wish you had a secure SSL-based login for it? Fear not, the answer is here!

Steps

Receive an SSL certificate. You can purchase one from a trusted company such as VeriSign, or generate your own with OpenSSL.
Apply the SSL certificate to your web server. If using Apache, you will need to enable the mod_ssl extension, and provide the location of the certificate. If using IIS, you will need to follow the wizards.
Confirm port 443 is open in any firewalls.
Verify that SSL is properly configured. Test to make sure that you can access https://localhost/ from the web server. If so, SSL is properly configured.
Create a login page in your favorite server-side programming language.

When working with Apache, you will need to restart the service after changing httpd.conf before your changes will take effect.
You can develop a login in your favorite language to use hard-coded credentials, database-stored credentials (plain-text, hashed, or encrypted), or even Active Directory credentials.

If you use a self-signed certificate, or a certificate signed by your internal CA, external users will be prompted to trust your certificate. Internet Explorer 7 highly suggests this is a bad thing to the end user.
Make sure your communications are encrypted all-around. Communications from the web server to the domain controller may be unencrypted. Use a packet-sniffer to help make sure your credentials are really secure.