The sites are correct. Mac OS X has drivers already installed for printing and scanning. To scan images in, launch the "Image Capture" application in your Applications folder. You should see your DeskJet listed on the left-hand side. Choose it and you will be able to scan from there.
Hope this helps,
Just looked som stuff up and there are issues with the Uninstaller and Snow Leopard. Please download and install the Apple drivers so it overwrites the HP drivers. Before installing, please unplug your DeskJet. You can find them here:
After you install, restart, then plug your DeskJet back in. Try scanning again.