For a new fresh install of Lion Sever in what order should you do the following;
Certificates
Opendirectory
DNS
Certificates
Opendirectory
DNS
If you're sure you need an Open Directory server,
If your machine supports it, I'd use Mountain Lion over Lion Server. Lion Server is rather half baked, caught between the old style Admin tools from earlier OS X Server versions, and the newer one. ML just works better.
I'm trying to create a server for a group of people that attended some language classes I was in. So to have a Web site and a Wiki
If you're just going to be doing web services and a Wiki for a small group of users, Open Directory probably isn't worth the trouble. Also note that to run an Open Directory Master, you need more than one CPU core, so it might run rather poorly in VMWare on your 2 core i5 Mini.
I'd still use Mountain Lion over Lion's server.