I'm not a noob, but I was ALSO having problems until I followed this USB Networking blog post. The instructions there also apply to usb/ethernet setup. Just follow along until you get to the part about "insmod .../g_ether.ko ; ifup usb0" and replace with "insmod your_ethernet_chipset_driver.ko ; ifup eth0".

For me, I first select the DEFAULT network, type "sudo insmod pegasus.ko", plug in the USB Ethernet dongle (plugged into a mini-USB OTG adapter), plug in the ethernet cable, then do "sudo ifup eth0". I do "sudo ifdown eth0" before I unplug everything. Hope that helps.