I have my own webserver running GL, I want to create a few more GL sites that are completly seperate installs. Should I create them under the apache/htdocs with sub directories for each site or should I use virtual hosts.
I am very new to apache but have been using GL for years.

For installation and security purposes its easiest to install GL in its own virtual host as a subdomain or other FQDN.

There's a nice tutorial (well, general outline of how to do it ...) on the Apache homepage: Dynamically configured mass virtual hosting.

With this setup, you simplly create a directory which is then mapped to a subdomain. So you create a directory "blah" and automatically get a vhost for blah.example.com.

I've used that in the past for an "instant Geeklog" setup: Enter the name of the subdomain in a form, a script copies the Geeklog files around, creates a database, runs the install script, and within seconds, you have a fully working Geeklog

bye, Dirk