Setting up a SMALL network

I am just starting to learn about XBEE 900 networking and have been looking for some documentation on how to set up a simple (say 3 XBees) network with RS-232 units on the two remote sites. Not one that simply says, “plug it in and use the components like it comes in the development package” but one that explains the a setup with, for example, all IPs being in the 10.2.n.m range and the RS-232 inputs having different characteristics. I have a feeling that there is probably a tutorial out there somewhere but I havent found it.

Thanks in advance for your help.