Setting up a HP printer in GNU/Linux is probably a lot easier to do then any other brand – mostly thanks to the awesome HPLIP. This short tutorial will explain how to set up CUPS and SANE to use a HP All-in-One printer with the integrated wireless print server (e.g. HP Photosmart C4380), because there is a small caveat that needs pointing out.
Once the printer is set up as a network printer and associated it with the LAN's SSID it is ready to be added in CUPS. But here is the trick: instead of selecting Find New Printers which finds (using Avahi, I presume) the printer on the ipp:/ URL, you should first run hp-setup and let it add the printer to CUPS using the hp:/ URL (e.g. hp:/net/Photosmart_C4380_series?ip=192.168.1.4).
When the printer is set up in CUPS as described above, all that is needed to have wireless printing in SANE is adding hpaio to /etc/sane.d/dll.conf on the client computer.
Then both remotely printing and scanning are ready. And all that without any need to have a computer running 24/7 as a server.