Assembly is pretty straight forward, though not recommended for people not used to soldering small SMD components.  

When the unit is tested using the test program on http://hardware.atari.org and all tests pass, you need to program the serial EEPROM.  The program for that is also on the above website.  Once that is done, you need to cut a track on the NETUS-Bee, this forces the RTL8019AS network chip to use the settings from the serial EEPROM.  The track connects to pin 65 called JP.  On the design I have done there is a small mark over this track in the print screen layer of the PCB.