Connect your 360 with a crossover cable to the wired network adapter on your PC.
Go to your wireless adapter, right click, bring up properties, go to advanced, enable ICS. Then goto settings and enable the following service ports: 88 UDP, 3074 TCP/UDP. Point them at your 360 which you should assign a static IP of 192.168.0.2
I suggest you switch off Windows Firewall, unless you want to configure that also, and it's not necessary as your router will likely have a firewall anyway.
Or if you want an easier solution, bridge together the wired and wireless adapter. I haven't had much success with this however, it will work fine, but if the wireless loses signal you have to remove it from the bridge and re-add it to get it working again, or at least in my experience.