SSL uses port 443 for requests for secure pages. If your browser just sits there for a long time when you attempt to access a secure page over your Apache proxy, then the proxy may not be configured to handle SSL. You need to instruct Apache to listen on port 443 in addition to any of the ports on which it is already listening:

    Listen 80
    Listen 443

Then set the security proxy in your browser to 443. That might be it!

If your proxy is sending requests to another proxy, then you may have to set the directive ProxyRemote differently. Here are my settings:

    ProxyRemote http://nicklas:80/ http://proxy.mayn.franken.de:8080
    ProxyRemote http://nicklas:443/ http://proxy.mayn.franken.de:443

Requests on port 80 of my proxy nicklas are forwarded to proxy.mayn.franken.de:8080, while requests on port 443 are forwarded to proxy.mayn.franken.de:443. If the remote proxy is not set up to handle port 443, then the last directive can be left out. SSL requests will only go over the first proxy.

Note that your Apache does NOT have to be set up to serve secure pages with SSL. Proxying SSL is a different thing from using it.