Very strange. Ok I will get on my computer soon and look for the links for you. But you can already start by going to the dev-team blog site and look for redsnow there, it's easy to locate the redsnow file on the dev-team blog. As for the ipsw you can get the one downloaded by your iTunes at this location in your computer:
You should first allow hidden file to be showed, you can clic organize >folder and search options. in the popup wondow clic on tab "view" then mark "show hidden files, folders and drives" when that's done go to
C: user > username(your comp user name) > appData > Roaming > apple computer > iTunes > iPhone Softwarw Updates. In that folder you will find your the ipsw which was downloaded by itunes and used by itunes to upgrade your iOS. you can copy, NOT CUT the ipsw to another location like to your desktop. You will need to use it with redsnow.
On a mac computer :
Home Folder/Library/Application Support/iTunes/iPod Firmware
Now you will also need to backup your iPhone files in iTunes by connecting the phone to your computer, open up iTunes and in the left panel you will see your iPhone icon, right click on that icon and select "backup" only after doing that you can start jailbreaking your phone. This is for just to be safe in case something goes wrong.
