Newbie: Request assistance on mysql/wiki layouts

Hi,

I will admit to being a newbie to mysql and the like. I have recently switched to dreamhost and am at the beginning of a steep learning curve and would like to have your help to avoid any mistakes at the beginning.

My website plan is the following.
Have a root domain. root.com that is only accessible to me - that part is easy.
Have a phpbb for the root.com site.
Create multiple subdomains of root.com with individual private wiki's and seperate user groups. Ie. users with permissions to edit a.root.com will not have rights to edit b.root.com.

My initial need is for ~16 subdomains (a - p) with possible expansion to an even larger number later.

What is the directory structure I should use for this?
Do I use a common MySQL database with seperate hostnames for each subdomain or shoudl I have a seperate database AND hostname for each subdomain. Also, do I install Mediawiki (or another wiki) under each subdomain (a.root.com, b.root.com) or do they all go in root.comwiki or root.comwa, root.comwb ect?

I have been unable to determine which directory structure will cause the least problems for future growth and management. I don't want to do something now that will cause me grief later.

Thanks,

Jeff

Unless you have some strong reason not to, I'd suggest using one mediawiki install and using custom namespaces [1] and possibly one of the namespace permissions plugins [2].


[1] http://www.mediawiki.org/wiki/Manual:Using_custom_namespaces

[2] http://www.mediawiki.org/wiki/Extension:Hierarchical_Namespace_Permissions

I want a gui editor so I am trying to install MoinMoin. Thanks anyways.