One CI install, One admin section, multiple sites?

[eluser]Devon Lambert[/eluser]
Apologies if this has been posted previously, I did do some searching but came up with nothing relating to this particular issue. I have a slightly different scenario than the typical "one CI install, multiple sites" to propose to you all.

I plan on a creating a series of sites that operate in the same realm/business model. I intend on building out a CMS specifically for this purpose. I will be the primary (read: Only) admin for all of these sites. Therefore I would like to create 1 simple admin section that can be used to manage all of them.

How would I go about doing this? (From a Database/code design perspective)

Are there any tutorials that you can point me towards?

Thank you.