If your network neighborhood only show 1 PC without showing your other one, then I think your network is not working properly. Get your network working perfectly before doing ICS, cuz ICS relies on the network working.
Make sure you have an unique 192.168.0.x for each computer, and the same 255.255.255.0 submask. Assign an unique name to each computer, but the same workgroup. Also make sure "File and Printer Sharing" is installed.
As for ICS, I personally use Sygate also. It's real easy to setup, just install Sygate using Server mode on the PC with the DSL, then at your other PC set the gateway to the IP of the first PC (eg. 192.168.0.1), and set DNS to the DNS of your DSL provider. And that's it! But make sure your network is working properly before doing this, cuz sygate assumes your network is working, it won't work unless ur network works.