The printer functionality of the Epson Expression Home XP-305 is fully supported by Linux. The printer can be accessed by the epson-201201w OpenPrinting printer driver, which supports the models 302, 303, 305, and 306.
The WiFi connection of the printer can be configured in Ubuntu by “System Settings -> Printers -> Add -> Network Printers”. After a short while, approximately 1 minute, the printer appears in the list. The corresponding printer driver gets downloaded semi-automatically (user confirm necessary).
It is also possible to configuration the WiFi connection of the printer with the Windows software that is provided with the printer and by using Wine. However, this kind of installation is overhead and should be prevented, if possible. After installing Wine the file “InstallNavi.exe” located on the installation CD of the All-in-One printer can be executed with Wine. After finishing all configuration steps of the program the WiFi connection to the printer gets activated (this can be seen on the LCD screen of the printer). Afterwards, the printer can be configured in Ubuntu like other printers, i.e. in the Ubuntu menu (top right) the printer configuration has to be selected in the shutdown menu. Then, the new printer can be added.
The scanner is currently not listed in the Sane database. It is not known, it is not known it the scanner can be used. (Please share your experiences in the comments section of this page)
Possibilities to access a sane scanner in Ubuntu are given in http://wiki.ubuntuusers.de/Epson-Scanner (in German).