Windows 7 - Windows 7 "simple" sharing tutorial needed!

I have multiple computers on my LAN. One is a newly converted to Windows 7 Professional equipped machine and the other 5 are Win XP. Here is what I need to do.
1) I need file sharing between the Windows 7 machine and my two file servers WITHOUT HAVING TO INPUT PASSWORDS.
2) I need the Windows 7 machine to be able to boot to life WITHOUT HAVING TO INPUT PASSWORDS or click user icons. These computers operate UNattended and if a power fail should occur, the Windows 7 machine must boot to life without human intervention.
3) Users on any of the XP machines must be able to access files on the Windows 7 Machine again without having to input passwords.

I am sure all this "you need permission to access this file" is nice in some applications, but not in mine. In fact, when I try to input my administrator password from one of the XP machines, I get a message that says "you do not have permission to perform this action." This even tho I am the administrator in all the machines and have the same username/PW in all the machines. How does one GET "permission" to read/write files between Windows 7 and XP machines?

Windows 7 tech support got to my User Page where the ()checkbox is to check "USERS MUST ENTER A PASSWORD TO ACCESS THIS COMPUTER". The unchecked the option and removed the password. This allowed the computer to boot up unattended. But when I went back and entered the system-wide password so users could access the Windows 7 machine, the login ocon came back and again the Windows 7 machine will not boot into operation without entering the username/PW. I am not able to find the User Page List again and the help file is no help. Any clues here?

Is there a way to disable all of these new "permissions" methodology so users can freely access between computers? One of my engineer associates says: "Avoid Windows 7 like the plague", but I am trying to persist and figure out how to use it.
Thanks!

Joe