This is really being posted by Yulia, you private msged me earlier, I just can't be bothered to log out of xarg's profile...I will talk to you later about Xerxes notes, just I don't have them here with me at xarg's house (funny enough I didn't plan to study while being here..hehehe) so...I don't know how much help it will be, but I'm fairly sure for this part you want to be looking up stuff about the Satrapies, how he divided the empire etc, the garrisons, things like that. Herodotus gives a lot of information about this, I'll be home tomorrow anyways and will be going back over my Xerxes stuff so I'll be able to help you then, but I'm sure there is a website...I can't remember it...that has the distance education/open high school stuff, if you can get hold of the distance education Xerxes booklets, I think there is 5 + 1 revision booklet, you will have everything that you need.
But basically from what I recall this section dealt a lot with the satrapies etc, what you have to remember that the admin of the empire was in large part set up by Darius, eg that huge road thing and communication etc...the rest was either changed or carried on by Xerxes...Darius' set up of the empire was carried on for I think...200 years or something, so maybe try seeing what you can find about Darius and then seeing what Xerxes changed...
I'll help you when I get home.
Good luck