1. Make sure both PCs have network cards configured for linux. SuSE must have some sort of admin tool for this, which also lets you set an IP number for each PC. Use say 192.168.1.1 and 192.168.1.2 (there is a reason for that, if you want to connect your network to the net at some point). Ignore all the DHCP, gateway, broadcast stuff.
2. Connect them with a 'crossover cable'. The common sort of ethernet cable connects a PC to a hub or switch, and is not the same thing.
3. Try to ping one from the other. e.g on 192.168.1.1 try
% ping 192.168.1.2
If you see something like
64 bytes from 192.168.1.2: icmp_seq=0 ttl=255 time=0.7 ms
then you are networked!
If no luck, ask again for more detailed advice.