n0ak

You have to:

#1 unload any g_nokia and g_storage_file modules eventually present

#2 load the module g_ether (and install the related driver in windows)

#3 bring up and configure the usb0 network adapter

If you want to share the 3g connection you ave also
to

#4 enable the ip forwarding

#5 set the iptables roule[s]

#6 configure statically the ip/gw/dns on the pc side or (better) configure dnsmasq on the n900 to act as DHCP/DNS server.


P.S. You need the power kernel to use iptables,

If you don't need the Internet sharing, you can use the stock kernel but you need the mad deveper package which provide the g_ether module