New Location Setup - have a checklist?

Hello all. Our current network consists of 2 locations. In Sept. we will be adding a 3rd location. I will have to create a new OU, GPO, user accounts, new Windows 2008R2 DC server, etc.

I am concerned this is an entirely new setup and that there are so many things that need to be done, I may forget to do something simple. Anyone have a checklist they use for something like this?

Thanks ~ Erik