Here is a nice book from Sun, Solaris Systems Programming, that should really challenge you. Be advised that it is not light reading. The writer's homepage has plenty of additional information as well.
Two other books you may want to look at are UNIX Network Programming, Volume 2: Interprocess Communications by W. Richard Stevens and Solaris Internals: Core Kernel Architecture, Vol. 1 by Jim Mauro and Richard McDougall.
Chapter 10 of the Trusted Solaris Developer's Guide offers a peek at interprocess communications. This Sun Developer Network article gives a detailed explanation of the concepts and implementation behind fast sockets, an alternative to IPCs. Click here to get an introduction to sockets.
This was first published in October 2005