Subnets really confuse me,
http://support.wrq.com/tutorials/tcpip/subnet1.html
I also often see 10.0.0.1 used for private addressing behind a proxy server. I've never understood that at all.
Basically I deal with IP addressing the same way I deal with JavaScript in that I've learned what works and enough to know what to put where, but don't have a complete understanding of why.
I do know that if you are setting up a network behind a router you can start with 192.168.1.2 on the computers and keep on adding 1 to each computer so that the next one would be 192.168.1.3 and so on and so on up to 195.168.1.244. The subnet stays the same at 255.255.255.0 and the router or gatway is 192.168.1.1.