i Have got a server with a wildcard already added and want to add another site that must be secure.
You can start of by adding another Web Application with a host header and using port 80.
On You Web Application:
Then open IIS 7.
To verify, check that there is a certificate loaded you can click on the server name on the left and go to Server Certificates
Then click on sites, go to your new Web Application and on the right click on bindings.
In SharePoint 2013 you also need to do this step:
Goto Central Administration -> Security -> Manage Trust
Click New, give it a name and browse to the existing Certificate CER file.
Under the bindings click on add and add your Secure details.
Type = https
Port = 443
Hostname = siteurl (no https)
SSL Certificate = The existing wildcard certificate.
Leave the http binding there for now. Can remove it later to create a redirect. (You can prob remove it now if you like...)
Remember that you will need a DNS entry for you new Host header..
To start of you can test and see if you can open your site with the normal url Sitename.domain.com, if that works try https://sitename.domain.com.
If the https works, go back to where you selected your site on IIS and select SSL Settings, change this to "Require SSL"
Then i must still add how to do a redirect from http to https...Basically create another site with http and redirect it to https site.