Ok, this may or may not be a large problem. But I could do with some help either way.
I am in the process of designing a medium size database, but i am having trouble working out exactly how I should set the Keys for the database and tables.

The 2 diagrams below, ER and DFD should help explain pretty much what i wish to acheive.

The main part that i am unsure about is the Sites table and its Keys.
In short, each site cannot have multiple streets, and each street can have multiple sites. So what i had thought about is giving each street a unique site number to that street. But i cannot perform a link between the Sites table and Notices table.

http://img151.imageshack.us/img151/3729/tmadatabasedesignerfw3.th.jpg (http://img151.imageshack.us/my.php?image=tmadatabasedesignerfw3.jpg)

http://img224.imageshack.us/img224/3572/tmadatabasedesigndfdyl8.th.jpg (http://img224.imageshack.us/my.php?image=tmadatabasedesigndfdyl8.jpg)
In the above diagram, all items within the large purple box will be part of an Access database, the items in the green box are an Excel spreadsheet.
A document with the each figure in the above diagram is attached to this post.

For the time being i shall leave you with the above information for any general feedback anyone may have.

I hope that isn't too difficult to understand.


For anyone thats wondering, the diagrams i have shown arn't really supposed to be the standard diagrams, but more something that can be used to help build/create the database.

Not to worry, after some careful thinking and pondering on a huge number of things, it is sorted.