It's available from and other place.

Armed with that, it's time to read

HP may have to reveal where the drivers are and what order to install them.

"but I know the XP installation should be pretty self-explanatory."

Sorry but after installing XP for too many years I can only share it's not self explanatory. The install routing has never been harder. Look at that link above. No one might have guessed that HP would hide drivers on a FTP server.