This method will not work! Apple has closed the signing window for iOS 5.0.1, so it is no longer a simple matter of downloading and installing that iOS. The only iOS that can be installed by "just downloading" it is iOS 5.1.
The only way, now, to put iOS 5.0.1 on your iPad1 is if you have SHSH blobs. And, you MUST create a custom IPSW using those blobs and the stock iOS 5.0.1 IPSW.
The instructional sticky I linked to a few posts up is the way to go. There is no other way to put firmware version 5.0.1 on an iPad1 so that you can jail break it with that iOS.